Relay adhesion detection circuit and system

Abstract

The invention provides a relay adhesion detection circuit and system, and relates to the technical field of relays, and the circuit comprises a control module, an isolation module and n detection modules. Wherein n is greater than or equal to 1. The first side of the isolation module is connected with the control module, and the second side of the isolation module is connected with the n detection modules. Each detection module comprises a relay to be detected and an acquisition module; the relay to be tested is connected with the second side of the isolation module and the acquisition module. The acquisition module is also connected with the second side of the isolation module and the control module. When the control module receives an adhesion detection instruction, the control module sends a starting instruction to the first side of the isolation module so as to drive the isolation module to work. The acquisition module acquires state data of the to-be-tested relay and sends the state data to the control module. The control module judges whether the to-be-tested relay is adhered according to the state data. The relay adhesion detection circuit can carry out safe and effective adhesion detection on one or more relays to be detected.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of relays, in particular to a relay sticking detection circuit and system. BACKGROUND

[0002] With the rapid development of the new energy industry, new energy vehicles are increasingly popular due to their low pollution and low energy consumption, and the market has higher requirements for their safety performance. As the core power source, the total voltage of the high-voltage battery pack is usually high, and the relay is a key switching device in the high-voltage safety system. Sticking of the relay contacts may occur during switching, and if this fault is not detected, it can easily cause a safety accident.

[0003] The common sticking detection methods currently use direct detection of the voltage across the relay or drive the optocoupler through a current-limiting resistor. However, such methods have safety hazards under high and low voltage conditions, and the difference in optocoupler drive current can easily cause device light decay or misdirecting, affecting the accuracy of the judgment. In addition, with the development of high-voltage topology structure, the number of high-voltage relays is increasing, and the existing detection methods cannot meet the detection needs of multi-relay systems.

[0004] In summary, how to effectively detect the sticking state of the relay while ensuring safety is a technical problem that needs to be solved by those skilled in the art. SUMMARY

[0005] The purpose of the present application is to provide a relay sticking detection circuit and system to effectively detect the sticking state of the relay while ensuring safety.

[0006] To achieve the above purpose, the technical solution adopted by the present application is as follows: On the one hand, the present application provides a relay sticking detection circuit, comprising: a control module, an isolation module and n detection modules; wherein n≥1; The first side of the isolation module is connected to the control module, and the second side of the isolation module is connected to n detection modules respectively; each detection module comprises a relay to be tested and an acquisition module; the relay to be tested is connected to the second side of the isolation module and the acquisition module respectively, and the acquisition module is further connected to the second side of the isolation module and the control module respectively; When the control module receives a sticking detection instruction, the control module is configured to send a start instruction to the first side of the isolation module to drive the isolation module to work; The acquisition module is configured to acquire state data of the relay to be tested and send the state data to the control module; The control module is further configured to determine whether the relay to be tested is sticking according to the state data.

[0007] Further, the isolation module is an isolation transformer, and the isolation transformer comprises a primary winding and n secondary windings; The same name end of the primary winding is connected with the control module, and the non-same name end of the primary winding is connected with a power supply; the same name end of the secondary winding is connected with one end of the relay to be tested, and the other end of the relay to be tested is connected with the acquisition module, and the acquisition module is further connected with the non-same name end of the secondary winding and the control module respectively.

[0008] Further, the n detection modules comprise x first detection modules, and the n secondary windings comprise x first secondary windings; wherein 1≤x≤n; Each first detection module comprises a first relay to be tested, an auxiliary relay and a first acquisition module, and the first acquisition module comprises a first resistor and an acquisition unit; One end of the first relay to be tested and one end of the auxiliary relay are connected with the same name end of the first secondary winding, and the other end of the first relay to be tested and the other end of the auxiliary relay are connected with one end of the first resistor, and the other end of the first resistor is connected with the non-same name end of the first secondary winding; the first input end and the second input end of the acquisition unit are connected in parallel across the first resistor, the output end of the acquisition unit is connected with the control module, and the control module is further connected with the auxiliary relay; the control module is used for controlling the conduction and the disconnection of the auxiliary relay according to the adhesion detection instruction.

[0009] Further, the adhesion detection instruction comprises a first relay to be tested adhesion detection instruction; When the control module receives the first relay to be tested adhesion detection instruction, the control module is used for driving the isolation transformer to work and controlling the auxiliary relay to be disconnected, so as to obtain the voltage difference across the first resistor through the acquisition unit; The control module is further used for judging whether the first relay to be tested is adhered according to the voltage difference across the first resistor.

[0010] Further, the adhesion detection instruction comprises an auxiliary relay adhesion detection instruction; When the control module receives the auxiliary relay adhesion detection instruction and the first relay to be tested is in the disconnected state, the control module is used for driving the isolation transformer to work and controlling the auxiliary relay to be conducted and disconnected, so as to obtain the first voltage difference and the second voltage difference through the acquisition unit respectively; wherein the first voltage difference is the voltage difference across the first resistor when the auxiliary relay is conducted, and the second voltage difference is the voltage difference across the first resistor when the auxiliary relay is disconnected. The control module is further configured to determine whether the auxiliary relay is stuck according to the first voltage difference and the second voltage difference.

[0011] Further, the n detection modules include y second detection modules, and the n secondary side windings include y second secondary side windings, where 1≤y≤n. Each second detection module includes a second relay to be tested and a second acquisition module, and the second acquisition module includes a second resistor, a current transformer, and an acquisition unit. One end of the second relay to be tested is connected to the like-named end of the second secondary side winding, the other end of the second relay to be tested is connected to one end of the second resistor, the other end of the second resistor is connected to the non-like-named end of the second secondary side winding to form a loop, the primary winding of the current transformer is connected in parallel across the second resistor, the first input end and the second input end of the acquisition unit are connected in parallel across the secondary winding of the current transformer, and the output end of the acquisition unit is connected to the control module. When the control module receives the stuck detection instruction, the control module is configured to drive the isolation transformer to work, the current transformer is configured to isolate the current signal of the loop in which the second resistor is located, the acquisition unit is configured to acquire the voltage difference across the second resistor through the current transformer and send the voltage difference to the control module, and the control module is further configured to determine whether the second relay to be tested is stuck according to the voltage difference across the second resistor.

[0012] Further, the n detection modules include z third detection modules, and the n secondary side windings include z third secondary side windings, where 1≤z≤n. Each third detection module includes a third relay to be tested and a third acquisition module, and the third acquisition module includes a third resistor and an acquisition unit. One end of the third relay to be tested is connected to the like-named end of the third secondary side winding, the other end of the third relay to be tested is connected to one end of the third resistor, the other end of the third resistor is connected to the non-like-named end of the third secondary side winding to form a loop, the first input end and the second input end of the acquisition unit are connected in parallel across the third resistor, and the output end of the acquisition unit is connected to the control module. When the control module receives the stuck detection instruction, the control module is configured to drive the isolation transformer to work, the acquisition unit is configured to acquire the voltage difference across the third resistor and send the voltage difference to the control module, and the control module is further configured to determine whether the third relay to be tested is stuck according to the voltage difference across the third resistor.

[0013] Further, the acquisition unit is a differential amplification circuit, a two-way ADC circuit or a metering chip.

[0014] Further, the control module comprises a controller, a switch tube and a fourth resistor. The first end of the switch tube is connected with the same end of the primary winding, the second end of the switch tube is grounded through the fourth resistor, and the control end of the switch tube is connected with the controller. When the controller receives the adhesion detection instruction, the controller sends a first level to the control end of the switch tube to turn on the switch tube, and the isolation transformer works under power.

[0015] In another aspect, the application also provides a relay adhesion detection system, which comprises the relay adhesion detection circuit according to any one of the preceding embodiments.

[0016] Compared with the prior art, the application has the following beneficial effects: The application provides a relay adhesion detection circuit and system, which comprises a control module, an isolation module and n detection modules, wherein n is greater than or equal to 1. The first side of the isolation module is connected with the control module, and the second side of the isolation module is connected with the n detection modules respectively. Each detection module comprises a relay to be tested and an acquisition module. The relay to be tested is connected with the second side of the isolation module and the acquisition module respectively, and the acquisition module is further connected with the second side of the isolation module and the control module respectively. When the control module receives an adhesion detection instruction, the control module is used to send a start instruction to the first side of the isolation module to drive the isolation module to work. The acquisition module is used to acquire state data of the relay to be tested and send the state data to the control module. The control module is further used to determine whether the relay to be tested is adhered according to the state data. Compared with the prior art, the application introduces an isolation module and a distributed detection architecture, realizes the safe isolation between the detection circuit and the high-voltage main loop, and constructs an extensible centralized detection circuit, so as to realize the effective detection of the adhesion state of a single or multiple relays to be tested under the premise of ensuring the safe isolation between the high-voltage and low-voltage systems. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0018] Figure 1 One of the circuit schematic diagrams of a relay sticking detection circuit provided by the embodiments of the present application; Figure 2 One of the circuit schematic diagrams of a relay sticking detection circuit provided by the embodiments of the present application; Figure 3 One of the circuit schematic diagrams of a relay sticking detection circuit provided by the embodiments of the present application; Figure 4 One of the circuit schematic diagrams of a differential amplification circuit provided by the embodiments of the present application; Figure 5 One of the circuit schematic diagrams of a two-way ADC circuit provided by the embodiments of the present application.

[0019] Icon: 10-relay sticking detection circuit; 100-control module; 110-controller; 200-isolation module; 300-detection module; 310-relay to be detected; 320-acquisition module; 400-first detection module; 410-first acquisition module; 500-second detection module; 510-second acquisition module; 600-third detection module; 610-third acquisition module; 700-acquisition unit; T1-isolation transformer; A-primary winding; B-secondary winding; B1-first secondary winding; B2-second secondary winding; B3-third secondary winding; SW1-assistant relay; K1-first relay to be detected; K2-second relay to be detected; K3-third relay to be detected; R1-first resistor; R2-second resistor; R3-third resistor; R4-fourth resistor; CT-current transformer; M1-switching tube. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be described clearly and completely in the present application with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0021] In the description of the present application, it should be noted that the relationship terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. The term "connection" should be interpreted broadly, for example, it can be a fixed connection, or a detachable connection, or an integral connection; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or a connection between two elements. For those skilled in the art, the specific meaning of the above-mentioned terms in the present application can be understood according to the specific circumstances.

[0022] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0023] Some embodiments of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments and features in the embodiments can be combined with each other without conflict.

[0024] As described in the background, the common adhesion detection method at present mostly uses direct detection of the voltage across the relay or drives the optocoupler through the current-limiting resistor. However, such methods have safety hazards under high and low voltage conditions, and the difference in driving current of the optocoupler easily leads to device light decay or misdirecting, affecting the accuracy of judgment. In addition, with the development of high-voltage topology structure, the number of high-voltage relays is increasing, and the existing detection method is difficult to meet the detection needs of the multi-relay system.

[0025] Therefore, how to realize effective detection of the adhesion state of the relay under the premise of ensuring safety is a technical problem to be solved by those skilled in the art.

[0026] To solve the above technical problems, please refer to Figure 1The embodiment of the application provides a relay sticking detection circuit 10, which comprises a control module 100, an isolation module 200 and n detection modules 300, wherein n is greater than or equal to 1.

[0027] The first side of the isolation module 200 is connected with the control module 100, and the second side of the isolation module 200 is connected with the n detection modules 300 respectively. Each detection module 300 comprises a to-be-detected relay 310 and an acquisition module 320, wherein the to-be-detected relay 310 is connected with the second side of the isolation module 200 and the acquisition module 320 respectively, and the acquisition module 320 is further connected with the second side of the isolation module 200 and the control module 100 respectively. Optionally, the to-be-detected relay 310 is an electromagnetic relay or a direct current contactor in a high-voltage system.

[0028] When the control module 100 receives a sticking detection instruction, the control module 100 is used for sending a starting instruction to the first side of the isolation module 200, so as to drive the isolation module 200 to work.

[0029] The acquisition module 320 is used for acquiring state data of the to-be-detected relay 310 and sending the state data to the control module 100.

[0030] The control module 100 is further used for judging whether the to-be-detected relay 310 is stuck according to the state data.

[0031] Compared with the prior art, the application realizes the safe isolation of the detection circuit and the high-voltage main loop by introducing the isolation module 200 and the distributed detection architecture, and meanwhile, a set of scalable centralized detection circuit is constructed, so that the effective detection of the sticking state of a single or multiple to-be-detected relays 310 is realized under the premise of ensuring the safe isolation of the high-voltage and low-voltage systems.

[0032] Specifically, the relay sticking detection circuit 10 provided by the application has the following advantages: (1) The safety is significantly improved. The isolation module 200 establishes an electrical isolation barrier between the high-voltage main loop and the detection circuit, thereby effectively preventing the high-voltage from entering the low-voltage detection loop, eliminating the safety hazards that may be caused in the detection process, and ensuring the safety of the system and personnel.

[0033] (2) The detection reliability is enhanced. The control module 100 uniformly sends a starting instruction, and each detection module 300 is driven through the isolation module 200, which replaces the dispersed driving mode of configuring an independent optical coupler for each relay in the traditional scheme. The centralized control mode eliminates the problems of light attenuation, false conduction and inaccurate judgment caused by the parameter differences of discrete devices (such as inconsistent optical coupler driving currents), and improves the detection accuracy and reliability.

[0034] (3) Good scalability, adapt to the development of high-voltage topology. The circuit adopts modular design, through a control module 100 and an isolation module 200, n detection modules 300 can be managed in parallel. When the number of relays in the high-voltage system increases, only the detection module 300 needs to be increased accordingly, without changing the core control and isolation architecture, so that the scheme can flexibly and economically adapt to the increasingly complex multi-relay system, solving the pain point of the lack of scalability of the existing detection method.

[0035] That is, the relay sticking detection circuit 10 provided by the application has safety, reliability and good scalability, and is suitable for high-voltage electrical systems such as new energy vehicles and energy storage systems.

[0036] Further, please refer to Figure 2 In the embodiment of the application, the isolation module 200 is an isolation transformer T1, and the isolation transformer T1 includes a primary winding A and n secondary windings B.

[0037] Wherein, the same name end of the primary winding A is connected with the control module 100, and the non-same name end of the primary winding A is connected with the power supply VCC. Each secondary winding B constitutes an independent detection circuit with a to-be-tested relay 310 and an acquisition module 320. Specifically, the same name end of the secondary winding B is connected with one end of the to-be-tested relay 310, the other end of the to-be-tested relay 310 is connected with the acquisition module 320, and the acquisition module 320 is also connected with the non-same name end of the secondary winding B and the control module 100 respectively.

[0038] When the control module 100 receives the sticking detection instruction, the control module 100 outputs a start instruction to make the primary winding A conductive. After the primary winding A is conductive, through the induced electromotive force, the same name end of all secondary windings B (i.e. the end with a black dot in the figure) will generate a high level. At this time, each acquisition module 320 starts to collect the state data of the to-be-tested relay 310 in the detection circuit where it is located, and sends it to the control module 100. The control module 100 can finally judge whether the corresponding to-be-tested relay 310 occurs sticking according to the received state data. Figure 2

[0039] As can be seen, by introducing the isolation transformer T1, not only a reliable high-voltage isolation safety barrier is constructed, but also modular multi-relay synchronous detection is realized. Moreover, the whole relay sticking detection circuit 10 has compact structure and small size of each device, which is convenient for realizing high integration through PCBA (Printed Circuit Board Assembly).

[0040] In addition, since the types of relays of different products are different, in order to adapt to the type difference of the to-be-tested relay 310, please refer to Figure 3 ​The embodiments of the present application provide a plurality of different types of detection modules 300.

[0041] For the relay 310 to be detected with voltage withstand requirements, in an optional embodiment, the n detection modules 300 include x first detection modules 400, and the n secondary windings B include x first secondary windings B1, where 1≤x≤n.

[0042] Each first detection module 400 includes a first relay K1 to be detected, an auxiliary relay SW1, and a first acquisition module 410. The first relay K1 to be detected is a relay that needs to meet a specific voltage withstand requirement. The auxiliary relay SW1 is an electromagnetic relay controlled by the control module 100, and its on-off state is directly controlled by the control module 100.

[0043] The first acquisition module 410 includes a first resistor R1 and an acquisition unit 700. One end of the first relay K1 to be detected and one end of the auxiliary relay SW1 are connected to the same end of the first secondary winding B1. The other end of the first relay K1 to be detected and the other end of the auxiliary relay SW1 are connected to one end of the first resistor R1. The other end of the first resistor R1 is connected to the non-same end of the first secondary winding B1. The first input end and the second input end of the acquisition unit 700 are connected in parallel across the first resistor R1. The output end of the acquisition unit 700 is connected to the control module 100, and the control module 100 is also connected to the auxiliary relay SW1.

[0044] The control module 100 is configured to control the conduction and disconnection of the auxiliary relay SW1 according to a sticking detection instruction. The sticking detection instruction includes a first relay K1 to be detected sticking detection instruction and an auxiliary relay SW1 sticking detection instruction.

[0045] As an optional embodiment, when the control module 100 receives the first relay K1 to be detected sticking detection instruction, the control module 100 is configured to drive the isolation transformer T1 to work and control the auxiliary relay SW1 to be disconnected, so as to obtain the voltage difference across the first resistor R1 through the acquisition unit 700. The control module 100 is also configured to determine whether the first relay K1 to be detected is stuck according to the voltage difference across the first resistor R1.

[0046] It can be understood that when it is necessary to detect the sticking state of the first relay K1 to be detected, the control module 100 drives the isolation transformer T1 to work and controls the auxiliary relay SW1 to be disconnected. The control module 100 detects the voltage difference across the first resistor R1 through the acquisition unit 700. If the voltage difference across the first resistor R1 is 0, it indicates that the first relay K1 to be detected is not stuck. On the contrary, if the voltage difference across the first resistor R1 is not 0, it indicates that the first relay K1 to be detected is stuck.

[0047] That is, when the auxiliary relay SW1 is disconnected and there is a voltage difference across the first resistor R1, it indicates that the first relay K1 under test is stuck. At this time, since the auxiliary relay SW1 is disconnected to play an isolation role, as long as the auxiliary relay SW1 selected meets the voltage withstand requirement, the first relay K1 under test can meet the voltage withstand requirement, thereby meeting the safety regulatory dielectric test requirement.

[0048] It can be seen that by adding the auxiliary relay SW1, not only the sticking detection of the first relay K1 under test can be realized, but also the safety regulatory dielectric test requirement can be met. However, at the same time, an additional relay is introduced, and the auxiliary relay SW1 may also have a sticking fault in the working process, so the auxiliary relay SW1 itself also needs to be detected for sticking.

[0049] As another optional implementation, when the control module 100 receives a sticking detection instruction of the auxiliary relay SW1 and the first relay K1 under test is in a disconnected state, the control module 100 is configured to drive the isolation transformer T1 to work and control the auxiliary relay SW1 to be turned on and off, so as to obtain a first voltage difference and a second voltage difference through the acquisition unit 700. The first voltage difference is a voltage difference across the first resistor R1 when the auxiliary relay SW1 is turned on, and the second voltage difference is a voltage difference across the first resistor R1 when the auxiliary relay SW1 is disconnected.

[0050] The control module 100 is further configured to determine whether the auxiliary relay SW1 is stuck according to the first voltage difference and the second voltage difference.

[0051] It can be understood that when the auxiliary relay SW1 needs to be detected for sticking, the first relay K1 under test is always in a disconnected state. When the control module 100 controls the auxiliary relay SW1 to be turned on, the acquisition unit 700 acquires a voltage difference across the first resistor R1 to obtain a first voltage difference. When the control module 100 controls the auxiliary relay SW1 to be disconnected, the acquisition unit 700 acquires a voltage difference across the first resistor R1 to obtain a second voltage difference. If the first voltage difference and the second voltage difference are different, it indicates that the auxiliary relay SW1 is not stuck. On the contrary, if the first voltage difference and the second voltage difference are the same, it indicates that the auxiliary relay SW1 is stuck.

[0052] For the relay 310 under test which needs to be isolated and has a voltage withstand requirement, in another optional implementation, the n detection modules 300 include y second detection modules 500, and the n secondary side windings B include y second secondary side windings B2, where 1≤y≤n.

[0053] Each second detection module 500 includes a second relay K2 under test and a second acquisition module 510. The second relay K2 under test is the relay which needs to be isolated and has a voltage withstand requirement.

[0054] The second acquisition module 510 comprises a second resistor R2, a current transformer CT and an acquisition unit 700. The second resistor R2 is connected between the second secondary winding B2 and the second resistor R2. The primary winding of the current transformer CT is connected in parallel to the second resistor R2. The first input end and the second input end of the acquisition unit 700 are connected in parallel to the secondary winding of the current transformer CT. The output end of the acquisition unit 700 is connected to the control module 100.

[0055] The current transformer CT is an isolation device. The size of the second resistor R2 can amplify the voltage difference between the two ends thereof, so as to facilitate subsequent detection and judgment.

[0056] When the control module 100 receives the adhesion detection instruction, the control module 100 is configured to drive the isolation transformer T1 to work. The current transformer CT is configured to isolate the current signal of the circuit in which the second resistor R2 is located. The acquisition unit 700 is configured to acquire the voltage difference between the two ends of the second resistor R2 through the current transformer CT and send the voltage difference to the control module 100. The control module 100 is further configured to determine whether the second relay K2 is adhered according to the voltage difference between the two ends of the second resistor R2.

[0057] Specifically, if the voltage difference between the two ends of the second resistor R2 is 0, it indicates that the circuit is disconnected and the second relay K2 is not adhered. On the contrary, if the voltage difference between the two ends of the second resistor R2 is not 0, it indicates that the circuit is formed and the second relay K2 is adhered.

[0058] For the ordinary relay 310, in another optional embodiment, the n detection modules 300 comprise z third detection modules 600, and the n secondary windings B comprise z third secondary windings B3, wherein 1≤z≤n.

[0059] Each third detection module 600 comprises a third relay K3 and a third acquisition module 610. The third relay K3 is an ordinary relay.

[0060] The third acquisition module 610 comprises a third resistor R3 and an acquisition unit 700. One end of the third relay K3 is connected to the same end of the third secondary winding B3. The other end of the third relay K3 is connected to one end of the third resistor R3. The other end of the third resistor R3 is connected to the non-same end of the third secondary winding B3, so as to form a circuit. The first input end and the second input end of the acquisition unit 700 are connected in parallel to the two ends of the third resistor R3. The output end of the acquisition unit 700 is connected to the control module 100.

[0061] When the control module 100 receives the adhesion detection instruction, the control module 100 is configured to drive the isolation transformer T1 to work. The acquisition unit 700 is configured to acquire a voltage difference across the third resistor R3 and send the voltage difference to the control module 100. The control module 100 is further configured to determine whether the third to-be-tested relay K3 is stuck according to the voltage difference across the third resistor R3.

[0062] Specifically, if the voltage difference across the third resistor R3 is 0, it indicates that the loop is disconnected, and the third to-be-tested relay K3 is not stuck. On the contrary, if the voltage difference across the third resistor R3 is not 0, it indicates that a loop has been formed, and the third to-be-tested relay K3 is stuck.

[0063] Based on the above design, the present application provides the first detection module 400 with the auxiliary relay SW1, the second detection module 500 with the current transformer CT, and the third detection module 600 with the third resistor R3 for different types of to-be-tested relays 310. Moreover, the number of the first detection module 400, the second detection module 500, and the third detection module 600 can be one or more, and different judgment logics can be selected according to the type of the to-be-tested relay 310, so as to meet the adhesion detection of all relays and DC contactors, and the application scenarios are flexible.

[0064] Further, as shown in FIG. 7, in the embodiment of the present application, the control module 100 includes a controller 110, a switch tube M1, and a fourth resistor R4. Figure 3

[0065] The first end of the switch tube M1 is connected to the same end of the primary winding A, the second end of the switch tube M1 is grounded through the fourth resistor R4, and the control end of the switch tube M1 is connected to the controller 110.

[0066] When the controller 110 receives the adhesion detection instruction, the controller 110 sends a first level to the control end of the switch tube M1 to make the switch tube M1 conductive, and the isolation transformer T1 is powered on to work.

[0067] Optionally, the switch tube M1 is an N-type MOS tube, and the first level is a high level.

[0068] In an optional embodiment, as shown in FIG. 8, the acquisition unit 700 is a differential amplification circuit; or, as shown in FIG. 9, the acquisition unit 700 is a two-way ADC circuit; or, the acquisition unit 700 is a metering chip. Figure 4 Figure 5

[0069] Optionally, the present application further provides a relay adhesion detection system, which includes the relay adhesion detection circuit 10 according to any one of the preceding embodiments.

[0070] ​​​In summary, by introducing the isolation transformer and the distributed detection architecture, the safety isolation between the detection circuit and the high-voltage main loop is realized, and a set of scalable centralized detection circuit is constructed, so as to realize the effective detection of the sticking state of a single or multiple relays to be detected under the premise of ensuring the safety isolation of the high and low voltage systems. Moreover, different judgment logics are adopted for different types of relays to be detected, and the application scenarios are flexible, and can meet the sticking detection of all relays and DC contactors.

[0071] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

[0072] It is obvious for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application. Any reference signs in the claims should not be regarded as limiting the claims.

Claims

1. A relay sticking detection circuit characterized by comprising: The application relates to a relay adhesion detection device. The device comprises a control module, an isolation module and n detection modules, wherein n>=1. The first side of the isolation module is connected with the control module, and the second side of the isolation module is connected with the n detection modules respectively. When the control module receives an adhesion detection instruction, the control module is used for sending a starting instruction to the first side of the isolation module to drive the isolation module to work. The collection module is used for collecting state data of the relay to be detected and sending the state data to the control module. The control module is further used for judging whether the relay to be detected is adhered according to the state data.

2. The relay sticking detection circuit according to claim 1, characterized by, The isolation module is an isolation transformer, and the isolation transformer comprises a primary winding and n secondary windings. The same name end of the primary winding is connected with the control module, and the non-same name end of the primary winding is connected with a power supply.

3. The relay sticking detection circuit according to claim 2, characterized by, The n detection modules comprise x first detection modules, and the n secondary windings comprise x first secondary windings, wherein 1<=x<=n. Each first detection module comprises a first relay to be detected, an auxiliary relay and a first collection module, and the first collection module comprises a first resistor and a collection unit. The same name end of the first secondary winding is connected with one end of the first relay to be detected and the auxiliary relay, and the other end of the first relay to be detected and the auxiliary relay is connected with one end of the first resistor.

4. The relay sticking detection circuit according to claim 3, characterized by, The other end of the first resistor is connected with the non-same name end of the first secondary winding. The first input end and the second input end of the collection unit are connected in parallel to the two ends of the first resistor. The output end of the collection unit is connected with the control module, and the control module is further connected with the auxiliary relay.

5. The relay sticking detection circuit according to claim 3, characterized by, The adhesion detection instruction comprises a first relay to be detected adhesion detection instruction. When the control module receives the first relay to be detected adhesion detection instruction, the control module is used for driving the isolation transformer to work and controlling the auxiliary relay to be disconnected, so as to obtain the voltage difference between the two ends of the first resistor through the collection unit. The control module is further used for judging whether the first relay to be detected is adhered according to the voltage difference between the two ends of the first resistor. The adhesion detection instruction comprises an auxiliary relay adhesion detection instruction. When the control module receives the auxiliary relay adhesion detection instruction, the control module is used for driving the isolation transformer to work and controlling the first relay to be detected to be disconnected, so as to obtain the voltage difference between the two ends of the first resistor through the collection unit. The control module is further used for judging whether the auxiliary relay is adhered according to the voltage difference between the two ends of the first resistor. When the control module receives the auxiliary relay sticking detection instruction and the first to-be-tested relay is in an open state, the control module is configured to drive the isolation transformer to work and control the auxiliary relay to turn on and off, so as to obtain a first voltage difference and a second voltage difference through the acquisition unit respectively; wherein the first voltage difference is a voltage difference between two ends of the first resistor when the auxiliary relay is turned on, and the second voltage difference is a voltage difference between two ends of the first resistor when the auxiliary relay is turned off. The control module is further configured to determine whether the auxiliary relay is stuck according to the first voltage difference and the second voltage difference.

6. The relay sticking detection circuit according to claim 2, characterized by, The n detection modules include y second detection modules, and the n secondary side windings include y second secondary side windings; wherein 1≤y≤n. Each second detection module includes a second to-be-tested relay and a second acquisition module, and the second acquisition module includes a second resistor, a current transformer and an acquisition unit. One end of the second to-be-tested relay is connected to the same-named end of the second secondary side winding, the other end of the second to-be-tested relay is connected to one end of the second resistor, and the other end of the second resistor is connected to the non-same-named end of the second secondary side winding to form a loop; the primary winding of the current transformer is connected in parallel across the two ends of the second resistor, the first input end and the second input end of the acquisition unit are connected in parallel across the two ends of the secondary winding of the current transformer, and the output end of the acquisition unit is connected to the control module. When the control module receives the sticking detection instruction, the control module is configured to drive the isolation transformer to work; the current transformer is configured to isolate the current signal of the loop in which the second resistor is located; the acquisition unit is configured to acquire the voltage difference across the second resistor through the current transformer and send it to the control module; and the control module is further configured to determine whether the second to-be-tested relay is stuck according to the voltage difference across the second resistor.

7. The relay sticking detection circuit according to claim 2, characterized by, The n detection modules include z third detection modules, and the n secondary side windings include z third secondary side windings; wherein 1≤z≤n. Each third detection module includes a third to-be-tested relay and a third acquisition module, and the third acquisition module includes a third resistor and an acquisition unit. One end of the third to-be-tested relay is connected to the same-named end of the third secondary side winding, the other end of the third to-be-tested relay is connected to one end of the third resistor, and the other end of the third resistor is connected to the non-same-named end of the third secondary side winding to form a loop; the first input end and the second input end of the acquisition unit are connected in parallel across the two ends of the third resistor, and the output end of the acquisition unit is connected to the control module. When the control module receives the sticking detection instruction, the control module is configured to drive the isolation transformer to work; the acquisition unit is configured to acquire the voltage difference across the third resistor and send it to the control module; and the control module is further configured to determine whether the third to-be-tested relay is stuck according to the voltage difference across the third resistor.

8. The relay stick detection circuit according to any one of claims 3 to 7, characterized in that, The acquisition unit is a differential amplification circuit, a two-way ADC circuit or a metering chip.

9. The relay sticking detection circuit according to claim 2, characterized by, The control module comprises a controller, a switch tube and a fourth resistor; a first end of the switch tube is connected with a same-named end of the primary winding, a second end of the switch tube is grounded through the fourth resistor, and a control end of the switch tube is connected with the controller; when the controller receives the adhesion detection instruction, the controller sends a first level to the control end of the switch tube, so that the switch tube is turned on, and the isolation transformer is powered on to work.

10. A relay sticking detection system characterized by comprising: The relay adhesion detection system comprises the relay adhesion detection circuit according to any one of claims 1-9.

Images