Relay adhesion detection circuit and relay adhesion detection method

Abstract

The invention relates to a relay adhesion detection circuit and a relay adhesion detection method. Comprising a pulse coupling module, a pulse detection module and a main control module, the pulse coupling module is used for receiving the pulse signals and coupling initial pulse signals in the pulse signals to the alternating current main loop; the pulse detection module is used for collecting a first detection signal in an alternating current main loop, processing the collected first detection signal to obtain a reflection signal, performing phase comparison on an initial pulse signal and the reflection signal, and outputting a phase difference feedback signal to the main control module; and the master control module is used for outputting the pulse signal to the pulse coupling module, receiving the phase difference feedback signal returned by the pulse detection module, and judging whether the relay is adhered or not according to a preset numerical value and the phase difference feedback signal. By adopting the method, the problems of high-voltage risk, complex judgment logic and high hardware cost of the existing relay adhesion detection method can be solved.

Description

Technical Field

[0001] The present application relates to the technical field of charging piles, and in particular, to a method and device for detecting relay adhesion and an adhesion detection system. Background Art

[0002] With the highly development of new energy vehicles, the equipment related to new energy vehicles has also developed rapidly. As a rigid configuration of new energy vehicles, while the charging piles are developing rapidly, the safety issues of charging piles have gradually attracted attention. On the basis of energy standards, international and domestic standards for special safety detection of charging piles have emerged. Whether it is international standards or domestic standards, relay adhesion detection is an important part of charging pile safety detection. Therefore, it is particularly important to detect the adhesion of relays.

[0003] The existing relay adhesion detection methods are mainly divided into two types: one is the multi-channel relay plus resistance sampling scheme, which determines whether the relay is adhered by closing different relay combinations and combining the voltage values of the sampling resistors; the other is the multi-channel relay plus isolation device scheme, which determines whether the relay is adhered by closing different relay combinations and combining the output states of isolation devices such as optocouplers. However, both of the above two adhesion detection methods have high-voltage risks, complex judgment logics, and high hardware costs.

[0004] However, for the existing relay adhesion detection methods, there are high-voltage risks, complex judgment logics, and high hardware costs, and no effective solutions have been proposed yet. Summary of the Invention

[0005] Based on this, it is necessary to provide a relay adhesion detection circuit and a relay adhesion detection method for the above technical problems.

[0006] In a first aspect, the present application provides a relay adhesion detection circuit. The circuit includes: a pulse coupling module, a pulse detection module, and a main control module;

[0007] The pulse coupling module is connected to the AC main circuit of the relay, and is configured to receive the pulse signal emitted by the main control module and couple the initial pulse signal in the pulse signal to the AC main circuit; the pulse signal includes the initial pulse signal and a real-time pulse signal;

[0008] The pulse detection module is connected to the pulse coupling module and the AC main circuit, and is used to collect a first detection signal in the AC main circuit, process the collected first detection signal to obtain a reflection signal, and perform a phase comparison between the initial pulse signal and the reflection signal, and output a phase difference feedback signal to the main control module; the first detection signal is a superimposed signal of the initial pulse signal and the reflection signal; the reflection signal is a signal reflected by the initial pulse signal at the break point of the line.

[0009] The main control module is connected to the pulse coupling module and the pulse detection module, and is used to output the pulse signal to the pulse coupling module, receive the phase difference feedback signal returned by the pulse detection module, and judge whether the relay is stuck according to a preset value and the phase difference feedback signal.

[0010] In one embodiment, the pulse detection module includes a pulse detection unit and a phase comparison unit;

[0011] The pulse detection unit is connected to the AC main circuit and the phase comparison unit, and is used to collect the first detection signal generated by the initial pulse signal in the AC main circuit, and transmit the second detection signal obtained after filtering and gain processing of the first detection signal to the phase comparison unit;

[0012] The phase comparison unit is connected to the pulse coupling module and the main control module, and is used to subtract the received second detection signal to obtain the reflection signal, and perform a phase comparison between the initial pulse signal and the reflection signal, and output the phase difference feedback signal to the main control module.

[0013] In one embodiment, the pulse detection unit includes a coupling subunit, a filtering subunit, and a gain subunit;

[0014] The coupling subunit is connected to the AC main circuit and the filtering subunit, and is used to collect the first detection signal generated by the initial pulse signal in the AC main circuit, and send the first detection signal to the filtering subunit;

[0015] The filtering subunit is connected to the gain subunit, and is used to filter the received first detection signal, and output the filtered first detection signal to the gain subunit;

[0016] The gain subunit is connected to the phase comparison unit, and is used to perform gain processing on the received filtered first detection signal to obtain the second detection signal and transmit it to the phase comparison unit.

[0017] In one embodiment, the phase comparison unit includes a difference sub-unit and a phase comparison sub-unit;

[0018] The difference sub-unit is connected to the pulse detection unit, the pulse coupling module and the phase comparison sub-unit, and is configured to perform a difference operation on the real-time pulse signal in the pulse signal output by the pulse coupling module and the received second detection signal, and output the reflection signal to the phase comparison sub-unit;

[0019] The phase comparison sub-unit is connected to the pulse coupling module and the main control module, and is configured to perform time delay control on the pulse signal output by the pulse coupling module to obtain the initial pulse signal in the pulse signal, and perform a phase comparison on the initial pulse signal and the received reflection signal, and output the phase difference feedback signal to the main control module.

[0020] In one embodiment, the pulse coupling module includes a filtering unit, a power amplifier unit and a coupling unit;

[0021] The filtering unit is connected to the main control module and the power amplifier unit, and is configured to receive the pulse signal transmitted by the main control module, filter the received pulse signal, and output the filtered pulse signal to the power amplifier unit;

[0022] The power amplifier unit is connected to the coupling unit, and is configured to perform a gain process on the received filtered pulse signal, and output the gain-processed pulse signal to the coupling unit;

[0023] The coupling unit is connected to the AC main circuit, and is configured to couple the initial pulse signal in the received gain-processed pulse signal to the AC main circuit.

[0024] In one embodiment, the coupling unit includes a first coupling sub-unit and a second coupling sub-unit;

[0025] The first coupling sub-unit includes a first coupling capacitor and a first switch, and is configured to couple the initial pulse signal to the first AC main circuit; one end of the first coupling capacitor is connected to the first AC main circuit, the other end is connected to one end of the first switch, and the other end of the first switch is connected to the power amplifier unit;

[0026] The second coupling sub-unit includes a second coupling capacitor and a second switch, and is configured to couple the initial pulse signal to the second AC main circuit; one end of the second coupling capacitor is connected to the second AC main circuit, the other end is connected to one end of the second switch, and the other end of the second switch is connected to the power amplifier unit;

[0027] The first AC main circuit is the live wire circuit of the relay; the second AC main circuit is the neutral wire circuit of the relay;

[0028] The coupling sub-unit includes a third coupling capacitor and a fourth coupling capacitor;

[0029] One end of the third coupling capacitor is connected to the first AC main circuit, and the other end of the third coupling capacitor is connected to the filtering sub-unit. The third coupling capacitor is used to collect the first detection signal in the first AC main circuit;

[0030] One end of the fourth coupling capacitor is connected to the second AC main circuit, and the other end of the fourth coupling capacitor is connected to the filtering sub-unit. The fourth coupling capacitor is used to collect the first detection signal in the second AC main circuit.

[0031] In a second aspect, the present application also provides a method for detecting relay adhesion. Applied to the relay adhesion detection circuit described in the first aspect above, the method includes:

[0032] The main control module transmits a pulse signal to the pulse coupling module;

[0033] The pulse coupling module couples the initial pulse signal in the received pulse signal to the AC main circuit of the relay;

[0034] The pulse detection module collects the first detection signal in the AC main circuit, processes the collected first detection signal to obtain a reflected signal, and compares the phases of the initial pulse signal and the reflected signal, and outputs a phase difference feedback signal to the main control module; the first detection signal is a superimposed signal of the initial pulse signal and the reflected signal; the reflected signal is a signal reflected by the initial pulse signal at the break point of the line;

[0035] The main control module determines whether the relay is adhered based on the received phase difference feedback signal from the pulse detection module and through a preset value.

[0036] In one embodiment, before the main control module determines whether the relay is adhered based on the received phase difference feedback signal from the pulse detection module and through a preset value, it further includes:

[0037] Based on the transmission distance of the initial pulse signal in the AC circuit, the length of the gun line of the charging pile where the relay is located, and the parameters of the line in the AC main circuit, the preset value is determined.

[0038] In one embodiment, the determining the preset value includes:

[0039] Determine the transmission speed of the initial pulse signal in the line based on the relative dielectric constant of the line of the AC main circuit;

[0040] Determine the wavelength of the initial pulse signal based on the transmission speed of the initial pulse signal in the line and the frequency of the initial pulse signal;

[0041] Determine a set first value based on the wavelength of the initial pulse signal and the first transmission distance of the initial pulse signal in the AC circuit;

[0042] Determine a set second value based on the wavelength of the initial pulse signal and the sum of the first transmission distance and the length of the gun line;

[0043] In one embodiment, the main control module determines whether the relay is stuck based on the phase difference feedback signal returned by the pulse detection module and received, and through a preset value, including:

[0044] When the phase difference feedback signal returned by the pulse detection module received by the main control module is equal to the set first value, it is determined that the relay is not stuck;

[0045] When the phase difference feedback signal returned by the pulse detection module received by the main control module is equal to the set second value, it is determined that the relay is stuck.

[0046] The above relay sticking detection circuit receives the pulse signal emitted by the main control module through the pulse coupling module, and couples the initial pulse signal in the pulse signal to the AC main circuit. Furthermore, the pulse detection module is used to collect the first detection signal in the AC main circuit, where the first detection signal is a superimposed signal of the initial pulse signal and the reflection signal. Furthermore, the collected first detection signal is processed to obtain the reflection signal, and the initial pulse signal and the reflection signal are phase - compared, and the phase difference feedback signal is output to the main control module. The main control module determines whether the relay is stuck through the actually received phase difference feedback signal, the preset value and the phase difference feedback signal. It determines whether the relay is stuck by presetting different phase difference feedback signals corresponding to different states of the relay and through the actually received phase difference feedback signal. In the whole judgment process, whether it is the pulse coupling process, the pulse detection process, or the phase comparison and relay state judgment process, there is no high - voltage involved. The judgment logic is simple and the safety is high, solving the problems that the existing relay sticking detection methods have high - voltage risks, complex judgment logics and high hardware costs.

[0047] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more concise and understandable. Description of the Drawings

[0048] The drawings described herein are provided to further understand the present application and form a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0049] Figure 1 is a first schematic structural diagram of a relay adhesion detection circuit provided by an embodiment of the present application;

[0050] Figure 2 is a second schematic structural diagram of a relay adhesion detection circuit provided by an embodiment of the present application;

[0051] Figure 3 is a third schematic structural diagram of a relay adhesion detection circuit provided by an embodiment of the present application;

[0052] Figure 4 is a fourth schematic structural diagram of a relay adhesion detection circuit provided by an embodiment of the present application;

[0053] Figure 5 is a fifth schematic structural diagram of a relay adhesion detection circuit provided by an embodiment of the present application;

[0054] Figure 6 is a flowchart of a relay adhesion detection method provided by an embodiment of the present application. Detailed Embodiments

[0055] To more clearly understand the purpose, technical solution, and advantages of the present application, the present application is described and illustrated below in conjunction with the drawings and embodiments.

[0056] Unless otherwise defined, technical or scientific terms used in this application shall have the ordinary meanings as understood by those of ordinary skill in the technical field to which this application pertains. In this application, words such as "a", "an", "one", "the", "these", etc. do not denote a limitation in quantity and can be singular or plural. The terms "include", "comprise", "have" and any variations thereof used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or modules (units) is not limited to the listed steps or modules (units), but may include unlisted steps or modules (units), or may include other steps or modules (units) inherent in these processes, methods, products or devices. The terms "connect", "be connected", "couple" and the like used in this application do not limit to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The term "plurality" used in this application means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, "A and / or B" may mean: A exists alone, A and B exist simultaneously, and B exists alone. Usually, the character " / " indicates that the objects associated before and after are in an "or" relationship. The terms "first", "second", "third", etc. used in this application only distinguish similar objects and do not represent a specific order for the objects.

[0057] See Figure 1 , Figure 1 is the first structural schematic diagram of the relay adhesion detection circuit provided by an embodiment of this application. As Figure 1 shown, the relay adhesion detection circuit includes: a pulse coupling module 110, a pulse detection module 120, and a main control module 130; the pulse coupling module 110 is connected to the AC main circuit 140 of the relay and is configured to receive the pulse signal emitted by the main control module 130 and couple the initial pulse signal in the pulse signal to the AC main circuit 140; the above pulse signal includes an initial pulse signal and a real-time pulse signal; the pulse detection 120 is connected to the pulse coupling module 110 and the AC main circuit 140, and is configured to collect a first detection signal in the AC main circuit 140, process the collected first detection signal to obtain a reflected signal, and perform a phase comparison between the initial pulse signal and the reflected signal, and output a phase difference feedback signal to the main control module 130. The above first detection signal is a superimposed signal of the initial pulse signal and the reflected signal. The above reflected signal is a signal reflected by the initial pulse signal at the break point of the circuit. The main control module 130 is connected to the pulse coupling module 110 and the pulse detection module 120, and is configured to output a pulse signal to the pulse coupling module 110, and receive the phase difference feedback signal returned by the pulse detection module 120, and determine whether the relay is adhered based on a preset value and the phase difference feedback signal.

[0058] The above-mentioned pulse coupling module 110 may include a coupling unit. The above-mentioned coupling unit is connected to the AC main circuit 140 of the relay and is used to receive the pulse signal emitted by the main control module 130 and couple the initial pulse signal in the received pulse signal to the AC main circuit 140. Among them, the above-mentioned coupling unit may be one or more of a coupling capacitor, a pulse transformer, a coupling network, etc. Among them, the above-mentioned initial pulse signal is a pulse signal with a preset time length that is initially coupled to the AC main circuit 140 through the pulse coupling module 110 during the relay adhesion detection process, and a reflection signal is detected at the target position of the AC main circuit 140, and a phase difference feedback signal is output after comparing the phases with the reflection signal. The above-mentioned real-time pulse signal is the pulse signal read in real time from the pulse signals continuously output according to a preset rule. It should be noted that in order to ensure that an accurate phase difference feedback signal can be obtained, the above-mentioned preset rule may be a preset fixed frequency. The above-mentioned preset fixed frequency can be specifically set according to specific requirements, and this embodiment does not make specific limitations here. The above-mentioned AC main circuit 140 may be a circuit formed by an AC input terminal, a relay, and an AC output terminal. The current flowing into the AC input terminal passes through the relay and is output from the AC output terminal.

[0059] In addition, the above-mentioned preset value and phase difference feedback signal may be the corresponding relationship of the specific values of the phase difference feedback signals corresponding to different states of the relay obtained through historical experimental data or through specific calculation methods based on the specific setting parameters and setting rules in the relay adhesion detection circuit.

[0060] It should be noted that when the relay adhesion detection circuit is designed, the specific position where the pulse is coupled into the AC main circuit 140 and the position where the first detection signal of the AC main circuit 140 is collected are both fixed. According to the parameters of the circuit, the transmission speed of the signal in the circuit can be determined. Based on the different transmission distances of the signal in the circuit in various states of the relay, the corresponding relationship of the specific values of the phase difference feedback signals corresponding to different states of the relay can be designed.

[0061] Generally, for relay adhesion detection, usually a multi-channel relay is combined with other devices respectively. By closing different relays and sampling other devices, it is judged whether the relay is adhered. During this process, because the relay is combined with other devices and the relay adhesion detection process is carried out under high voltage, electric shock may occur.

[0062] In view of the above situation, in this embodiment, outside the AC main circuit 140 where the relay is located, a pulse coupling module 110 for coupling an initial pulse signal to the AC main circuit 140 of the relay is provided, a pulse detection module 120 for collecting a first detection signal in the AC main circuit 140 where the relay is located is provided, and the pulse detection module 120 is used to obtain a phase difference feedback signal based on the first detection signal. A main control module 130 is provided to output a pulse signal to the pulse coupling module 110, receive the phase difference feedback signal transmitted back by the pulse detection module 120, and determine whether the relay is stuck through a preset value and the phase difference feedback signal. Whether it is the main control module 130, the pulse coupling module 110 or the pulse detection module 120, none of them is serially connected to the main circuit of the relay. What is involved is a pulse signal or a sine-cosine signal obtained after processing the pulse signal, not a high-voltage signal, and it does not need to be carried out under a high-voltage state. The judgment logic is simple and the safety is high, solving the problems of the existing relay adhesion detection method, which has a high-voltage risk, a complex judgment logic and a high hardware cost.

[0063] Among them, as an implementable manner, Figure 2 is the second structural schematic diagram of the relay adhesion detection circuit provided by the embodiment of the present application. As Figure 2 shown, the pulse detection module 120 includes a pulse detection unit 122 and a phase comparison unit 124; the pulse detection unit 122 is connected to the AC main circuit 140 and the phase comparison unit 124, and is used to collect a first detection signal generated by the initial pulse signal in the AC main circuit 140, and transmit the second detection signal obtained after filtering and gain processing of the first detection signal to the phase comparison unit 124; the phase comparison unit 124 is connected to the pulse coupling module 110 and the main control module 130, and is used to subtract the received second detection signal to obtain a reflection signal, and perform a phase comparison between the initial pulse signal and the reflection signal, and output a phase difference feedback signal to the main control module 130.

[0064] In this embodiment, whether it is the pulse detection unit 122 or the phase comparison unit 124, neither of them is serially connected to the main circuit of the relay. What is involved is a pulse signal or a sine-cosine signal obtained after processing the pulse signal, not a high-voltage signal, and it does not need to be carried out under a high-voltage state. The judgment logic is simple and the safety is high.

[0065] Specifically, as an implementable manner, Figure 3 is the third structural schematic diagram of the relay adhesion detection circuit provided by the embodiment of the present application. As Figure 3As shown, the pulse detection unit 122 includes a coupling subunit 1222, a filtering subunit 1224, and a gain subunit 1226; the coupling subunit 1222 is connected to the AC main circuit 140 and the filtering subunit 1224, and is configured to collect a first detection signal generated by an initial pulse signal in the AC main circuit 140 and send the first detection signal to the filtering subunit 1224; the filtering subunit 1224 is connected to the gain subunit 1226, and is configured to filter the received first detection signal and output the filtered first detection signal to the gain subunit 1226; the gain subunit 1226 is connected to the phase comparison unit 124, and is configured to perform a gain process on the received filtered first detection signal to obtain a second detection signal and transmit the second detection signal to the phase comparison unit 124.

[0066] In this embodiment, the above-mentioned coupling subunit 1222 can be one or more of a coupling capacitor, an isolation amplifier, an AC-coupled single-supply comparator, an isolation error amplifier, and a software-configurable AC / DC coupling module, etc. The above-mentioned filtering subunit 1224 can be a BPF (Band-Pass Filter). The above-mentioned band-pass filter can be a passive band-pass filter (such as an RC band-pass filter or an RLC band-pass filter, etc.) or an active band-pass filter (such as a twin-T band-pass filter or a multiple-feedback band-pass filter, etc.). By setting the band-pass filter, the filtering subunit 1224 allows signals within a specific frequency range to pass through, while attenuating or blocking signals below and above this frequency range, and is used to selectively extract the received first detection signal to obtain an accurate second detection signal, and further obtain an accurate phase difference feedback signal to achieve an accurate judgment of the relay adhesion detection. The above-mentioned specific frequency range can be specifically set according to specific requirements, and this embodiment does not make specific limitations here.

[0067] Among them, the above-mentioned gain subunit 1226 can be an automatic gain control (AGC, Automatic Gain Control) module, which is configured to dynamically adjust the gain of the received filtered first detection signal to ensure that the amplitude of the output second detection signal is stabilized within a preset range. The above-mentioned preset range can be specifically set according to specific requirements, and this embodiment does not make specific limitations here. The above-mentioned automatic gain control module can be implemented in one of the ways such as an analog AGC circuit, a digital AGC circuit, or a software algorithm. Because the pulse signal will attenuate during transmission in the circuit, therefore, before performing the subtraction, performing a gain on the signal can increase the amplitude of the second detection signal.

[0068] In this embodiment, neither the coupling subunit 1222, the filtering subunit 1224 nor the gain subunit 1226 is serially connected to the main circuit of the relay. The signals involved are pulse signals or sine and cosine signals obtained after processing pulse signals, not high-voltage signals, and there is no need to operate under high-voltage conditions. The judgment logic is simple and the safety is high.

[0069] In addition, as an implementable manner, Figure 4 is the fourth structural schematic diagram of the relay adhesion detection circuit provided by the embodiment of the present application. As Figure 4 shown, the phase comparison unit 124 includes a difference-making subunit 1242 and a phase comparison subunit 1244. The difference-making subunit 1242 is connected to the pulse detection unit 122, the pulse coupling module 110 and the phase comparison subunit 1244, and is used to subtract the real-time pulse signal in the pulse signal output by the pulse coupling module 110 from the received second detection signal, and output a reflection signal to the phase comparison subunit 1244. The phase comparison subunit 1244 is connected to the pulse coupling module 110 and the main control module 130, and is used to perform time delay control on the pulse signal output by the pulse coupling module 110 to obtain the initial pulse signal in the pulse signal, and compare the phase of the initial pulse signal with the received reflection signal, and output a phase difference feedback signal to the main control module 130.

[0070] The above-mentioned difference-making subunit 1242 can be a subtractor. The above-mentioned subtractor is used to subtract the real-time pulse signal in the pulse signal output by the pulse coupling module 110 from the received second detection signal to obtain a reflection signal. The above-mentioned phase comparison subunit 1244 can be a phase discriminator. The above-mentioned phase discriminator is used to compare the phase of the initial pulse signal with the received reflection signal and output a phase difference feedback signal. The above-mentioned phase difference feedback signal can be presented in the form of a voltage signal.

[0071] In this embodiment, neither the difference-making subunit 1242 nor the phase comparison subunit 1244 is serially connected to the main circuit of the relay. The signals involved are pulse signals or sine and cosine signals obtained after processing pulse signals, not high-voltage signals, and there is no need to operate under high-voltage conditions. The judgment logic is simple and the safety is high.

[0072] In addition, as an implementable manner, Figure 5 is the fifth structural schematic diagram of the relay adhesion detection circuit provided by the embodiment of the present application. As Figure 5As shown in the figure, the pulse coupling module 110 includes a filtering unit 112, a power amplifier unit 114, and a coupling unit 116; the filtering unit 112 is connected to the main control module 130 and the power amplifier unit 114, and is configured to receive the pulse signal transmitted by the main control module 130, filter the received pulse signal, and output the filtered pulse signal to the power amplifier unit 114; the power amplifier unit 114 is connected to the coupling unit 116, and is configured to perform gain processing on the received filtered pulse signal, and output the amplified pulse signal to the coupling unit 116; the coupling unit 116 is connected to the AC main circuit 140, and is configured to couple the initial pulse signal in the received amplified pulse signal to the AC main circuit 140.

[0073] Specifically, the above-mentioned coupling unit 116 is further connected to a phase comparison sub-unit 1244. The phase comparison sub-unit 1244 is configured to perform time delay control on the pulse signal output by the coupling unit 116 to obtain the initial pulse signal in the pulse signal.

[0074] Among them, the above-mentioned filtering unit 112 can be an LPF (Low-Pass Filter). The above-mentioned low-pass filter can be a passive low-pass filter such as an RC low-pass filter, an RL low-pass filter, or an LC low-pass filter, or an active low-pass filter. By setting the low-pass filter, the received pulse signal is subjected to low-pass filtering and smoothing processing to obtain a smooth signal, which is convenient for subsequent gain processing of the smoothed signal to obtain an amplified pulse signal.

[0075] In this embodiment, neither the filtering unit 112, the power amplifier unit 114, nor the coupling unit 116 is serially connected to the main circuit of the relay. The signals involved are pulse signals or sine and cosine signals obtained after pulse signal processing, and do not involve high-voltage signals. There is no need to operate under high-voltage conditions, the judgment logic is simple, and the safety is high.

[0076] In addition, as an implementable manner, the coupling unit 116 includes a first coupling subunit and a second coupling subunit; the first coupling subunit includes a first coupling capacitor and a first switch, and is configured to couple an initial pulse signal to the first AC main circuit; one end of the first coupling capacitor is connected to the first AC main circuit, the other end is connected to one end of the first switch, and the other end of the first switch is connected to the power amplifier unit 114; the second coupling subunit includes a second coupling capacitor and a second switch, and is configured to couple the initial pulse signal to the second AC main circuit; one end of the second coupling capacitor is connected to the second AC main circuit, the other end is connected to one end of the second switch; the other end of the second switch is connected to the power amplifier unit 114; the first AC main circuit is the live wire circuit of the relay; the second AC main circuit is the neutral wire circuit of the relay; the coupling subunit 1222 includes a third coupling capacitor and a fourth coupling capacitor; one end of the third coupling capacitor is connected to the first AC main circuit, the other end of the third coupling capacitor is connected to the filtering subunit 1224, and the third coupling capacitor is configured to collect a first detection signal in the first AC main circuit; one end of the fourth coupling capacitor is connected to the second AC main circuit, the other end of the fourth coupling capacitor is connected to the filtering subunit 1224, and the fourth coupling capacitor is configured to collect a first detection signal in the second AC main circuit.

[0077] The above-mentioned first coupling subunit realizes the coupling of the pulse signal through the opening and closing of the first switch. Specifically, when the first switch is closed, the first coupling capacitor is connected to the power amplifier unit 114, and the initial pulse signal in the pulse signal output with gain by the power amplifier module is coupled to the first AC main circuit. The above-mentioned second coupling subunit realizes the coupling of the pulse signal through the opening and closing of the second switch. Specifically, when the second switch is closed, the second coupling capacitor is connected to the power amplifier unit 114, and the initial pulse signal in the pulse signal output with gain by the power amplifier module is coupled to the second AC main circuit. In this preferred embodiment, through the combination of the switch and the coupling capacitor, and through the on-off of the switch, the coupling of different pulse signals to different AC circuits is realized. In this process, the judgment logic is simple and does not involve high-voltage signals, so the safety is high.

[0078] This embodiment also provides a method for detecting relay adhesion. Figure 6 It is a flowchart of the method for detecting relay adhesion provided by an embodiment of the present application. As Figure 6 shown, the process includes the following steps:

[0079] Step S610, the main control module 130 transmits a pulse signal to the pulse coupling module 110;

[0080] Step S620, the pulse coupling module 110 couples the initial pulse signal in the received pulse signal to the AC main circuit 140 of the relay;

[0081] Step S630: The pulse detection module 120 collects the first detection signal in the AC main circuit 140, processes the collected first detection signal to obtain a reflected signal, and compares the phases of the initial pulse signal and the reflected signal, and outputs a phase difference feedback signal to the main control module 130; the first detection signal is a superimposed signal of the initial pulse signal and the reflected signal; the reflected signal is the signal reflected by the initial pulse signal at the breakpoint of the line.

[0082] Step S640: The main control module 130 determines whether the relay is stuck based on the received phase difference feedback signal from the pulse detection module 120 and a preset value.

[0083] Specifically, the main control module 130 emits a pulse signal with a fixed frequency to the pulse coupling module 110. The pulse coupling module 110 couples the initial pulse signal in the received pulse signal to the AC main circuit 140 of the relay at a preset first position. The pulse detection module 120 collects the first detection signal at a preset second position in the AC main circuit 140, processes the collected first detection signal to obtain a reflected signal, and compares the phases of the initial pulse signal and the reflected signal, and outputs a phase difference feedback signal to the main control module 130. The main control module 130 determines the relay state corresponding to the current phase difference feedback signal according to the corresponding relationship between the preset relay state and the phase difference feedback signal value, and obtains the detection result of whether the relay is stuck. In this process, the preset first position and the preset second position can be fixed positions after the hardware layout of the relay stuck detection device is completed. When the preset first position and the preset second position are determined, the line through which the signal flows from the preset first position to the preset second position is fixed, and the corresponding relationship between the preset relay state and the phase difference feedback signal value is fixed. It should be noted that the preset first position and the preset second position can be changed. When the preset first position and the preset second position change, the phase difference feedback signal value corresponding to the preset relay state changes accordingly.

[0084] In the above steps S610 to S640, by coupling a pulse signal into the AC main circuit 140 of the relay and collecting a first detection signal at another position of the AC main circuit 140, processing the collected first detection signal to obtain a reflection signal, and then comparing the phases of the initial pulse signal and the reflection signal to obtain a phase difference feedback signal. Furthermore, based on the obtained phase difference feedback signal and a preset value, it is determined whether the relay is stuck. In the whole determination process, devices such as auxiliary relays, optocouplers, and sampling resistors are not required. By introducing a pulse coupling module 110 and a pulse detection module 120, only the subtraction of pulse signals and the comparison of phase differences are involved, without any high voltage involved. The judgment logic is simple and the safety is high, solving the problems of the existing relay sticking detection method, such as high voltage risk, complex judgment logic, and high hardware cost.

[0085] In one embodiment, before step S640, it further includes:

[0086] Step S632, determining a preset value based on the transmission distance of the initial pulse signal in the AC circuit, the length of the gun line of the charging pile where the relay is located, and the parameters of the line in the AC main circuit 140.

[0087] In this step, the above-mentioned transmission distance of the initial pulse signal in the AC circuit can be the distance from the position where the initial pulse signal is coupled to the AC main circuit 140 as the starting point to the position where the first detection signal is collected as the end point, that is, the transmission distance of the initial pulse signal from the starting point to the end point in the AC circuit. The above-mentioned gun line length can vary according to specific application scenarios and installation positions. Generally, the gun line length of a household charging pile is about 3 meters. The above-mentioned parameters of the line can be the relative dielectric constant of the line.

[0088] Specifically, in one embodiment, the above-mentioned determination of the preset value includes:

[0089] Step S1, determining the transmission speed of the initial pulse signal in the line based on the relative dielectric constant of the line in the AC main circuit 140.

[0090] The specific calculation process for determining the transmission speed of the initial pulse signal in the line is as follows:

[0091]

[0092] where, v p is the transmission speed of the initial pulse signal in the line, c is the speed of light, and ε r is the relative dielectric constant of the line.

[0093] Step S2: Determine the wavelength of the initial pulse signal based on the transmission speed of the initial pulse signal in the circuit and the frequency of the initial pulse signal.

[0094] The calculation process for determining the wavelength λ of the initial pulse signal is as follows:

[0095]

[0096] Where f is the frequency of the initial pulse signal.

[0097] Step S3: Determine the set first value based on the wavelength of the initial pulse signal and the first transmission distance of the initial pulse signal in the AC circuit.

[0098] The above preset first value is the value of the phase difference feedback signal corresponding to the non - adhesion of the relay, and it is the value of the phase difference feedback signal when the transmission distance of the initial pulse signal in the AC circuit is the first transmission distance. For example, the voltage value of the preset first value is V1.

[0099] In this step, the relationship between the transmission distance of the initial pulse signal in the AC circuit, the wavelength of the initial pulse signal, and the value of the phase difference feedback signal corresponding to the transmission distance of the initial pulse signal in the AC circuit can be expressed as:

[0100]

[0101] Where y is the transmission distance of the initial pulse signal in the AC circuit, λ is the wavelength of the initial pulse signal, and Δφ is the phase difference corresponding to the transmission distance of the initial pulse signal in the AC circuit. Among them, there is a corresponding relationship between the above - mentioned phase difference and the value of the phase difference feedback signal corresponding to the transmission distance of the initial pulse signal in the AC circuit, and the specific corresponding relationship is related to the parameters of the phase discriminator. For different phase discriminators, the corresponding relationship between the phase difference and the value of the phase difference feedback signal is different.

[0102] Step S4: Determine the set second value based on the wavelength of the initial pulse signal and the sum of the first transmission distance and the length of the gun line. For example, the voltage value of the preset second value is V3.

[0103] The above preset second value is the value of the phase difference feedback signal corresponding to the adhesion of the relay, and it is the value of the phase difference feedback signal when the transmission distance of the initial pulse signal in the AC circuit is the sum of the first transmission distance and the length of the gun line.

[0104] In the above steps S1 to S4, the set first value and the set second value are determined based on the transmission distance of the initial pulse signal on the AC loop and the length of the gun line. By setting the values, it is convenient to subsequently determine whether the relay is stuck based on the relationship between the actually measured phase difference feedback signal and the set values.

[0105] In addition, in one embodiment, in step S640, the main control module 130 determines whether the relay is stuck based on the phase difference feedback signal received and returned by the pulse detection module 120 and through a preset value, including:

[0106] In step S642, when the phase difference feedback signal received and returned by the main control module 130 from the pulse detection module 120 is equal to the set first value, it is determined that the relay is not stuck;

[0107] In step S644, when the phase difference feedback signal received and returned by the main control module 130 from the pulse detection module 120 is equal to the set second value, it is determined that the relay is stuck.

[0108] In the above steps S642 to S644, it is determined whether the relay is stuck based on the relationship between the actually measured phase difference feedback signal and the set value. The entire determination process is only a comparison of values, the judgment logic is simple, it does not involve high voltage, and the safety is high, solving the problems of the existing relay sticking detection method, which has a high voltage risk, a complex judgment logic, and a high hardware cost.

[0109] Preferably, assume that in the main circuit of the relay, the length of the live wire is 0.1 meter, the length of the neutral wire in the main circuit is 0.1 meter, and the length of the gun line is 5 meters. When the frequency of the pulse signal is fixed, through calculation, the voltage value of the phase difference feedback signal corresponding to the signal transmission line length of 0.1 meter is V1, the voltage value of the phase difference feedback signal corresponding to the sum of the lengths of the signal transmission live wire and the neutral wire, 0.2 meter, is V2, the voltage value of the phase difference feedback signal corresponding to the length of the signal transmission live wire or neutral wire plus the gun line, 5.1 meters, is V3, and the voltage value of the phase difference feedback signal corresponding to the sum of the lengths of the signal transmission live wire, neutral wire, and two gun lines, 10.2 meters, is V4. Set V1 as the set first value, set V3 as the set second value, set V2 as the set third value, and set V4 as the set fourth value. Furthermore, the main control module 130 determines the state of the relay based on the relationship between the voltage value V of the phase difference feedback signal received and returned by the pulse detection module 120 and each set value. When V = V1, it is determined that the relay is not stuck; when V1 ≤ V < V2, it is determined that the zero-fire short circuit occurs at the board end output; when V2 ≤ V < V3, it is determined that there is a break in the gun line; when V = V3, it is determined that the relay is stuck; when V ≥ V4, it is determined that the zero-fire short circuit occurs at the board end output.

[0110] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementation manners, and will not be elaborated herein again.

[0111] It should be understood that the specific embodiments described herein are only used to explain this circuit structure, rather than to limit it. All other embodiments obtained by those of ordinary skill in the art according to the embodiments provided in this application without creative work fall within the protection scope of this application.

[0112] Obviously, the accompanying drawings are only some examples or embodiments of this application. For those of ordinary skill in the art, this application can also be applied to other similar situations based on these drawings without creative work. Additionally, it can be understood that although the work done during this development process may be complex and time-consuming, for those of ordinary skill in the art, certain design, manufacturing, or production changes based on the technical content disclosed in this application are only conventional technical means and should not be regarded as insufficient disclosure of this application.

[0113] The term "embodiment" in this application means that the specific features, structures, or characteristics described in connection with the embodiment may be included in at least one embodiment of this application. The phrase appears in various positions in the specification and does not necessarily mean the same embodiment, nor does it mean being independent or alternative to other embodiments and mutually exclusive. Those of ordinary skill in the art can clearly or implicitly understand that the embodiments described in this application can be combined with other embodiments without conflict.

[0114] The above-described embodiments only represent several implementation manners of this application. Their descriptions are relatively specific and detailed, but should not be construed as a limitation on the scope of patent protection. It should be noted that for those of ordinary skill in the art, without departing from the concept of this application, several modifications and improvements can still be made, and these all belong to the protection scope of this application. Therefore, the protection scope of this application should be subject to the appended claims.

Claims

1. A relay adhesion detection circuit, characterized in that: include: Pulse coupling module, pulse detection module and main control module; The pulse coupling module is connected to the AC main circuit of the relay, and is used to receive the pulse signal emitted by the main control module, and couple the initial pulse signal in the pulse signal to the AC main circuit; the pulse signal includes the initial pulse signal and the real-time pulse signal; The pulse detection module is connected to the pulse coupling module and the AC main circuit, and is used to collect a first detection signal in the AC main circuit, process the collected first detection signal to obtain a reflection signal, perform phase comparison between the initial pulse signal and the reflection signal, and output a phase difference feedback signal to the main control module; The first detection signal is a superposition signal of the initial pulse signal and the reflected signal; the reflected signal is a signal of the initial pulse signal reflected at a breakpoint of the line; The main control module is connected to the pulse coupling module and the pulse detection module, and is used to output the pulse signal to the pulse coupling module, and receive the phase difference feedback signal sent back by the pulse detection module, and determine whether the relay is stuck through a preset value and the phase difference feedback signal.

2. The relay adhesion detection circuit according to claim 1, characterized in that: The pulse detection module includes a pulse detection unit and a phase comparison unit; The pulse detection unit is connected to the AC main circuit and the phase comparison unit, and is used to collect the first detection signal generated by the initial pulse signal in the AC main circuit, and transmit the second detection signal obtained after filtering and gain processing the first detection signal to the phase comparison unit; The phase comparison unit is connected to the pulse coupling module and the main control module, and is used to perform a difference on the received second detection signal to obtain the reflected signal, and to perform a phase comparison between the initial pulse signal and the reflected signal, and output the phase difference feedback signal to the main control module.

3. The relay adhesion detection circuit according to claim 2, characterized in that: The pulse detection unit includes a coupling subunit, a filtering subunit and a gain subunit; The coupling subunit is connected to the AC main circuit and the filtering subunit, and is used to collect the first detection signal generated by the initial pulse signal in the AC main circuit, and send the first detection signal to the filtering subunit; The filter subunit is connected to the gain subunit and is used to filter the received first detection signal and output the filtered first detection signal to the gain subunit; The gain subunit is connected to the phase comparison unit and is used to perform gain processing on the received filtered first detection signal to obtain the second detection signal and transmit it to the phase comparison unit.

4. The relay adhesion detection circuit according to claim 2, characterized in that: The phase comparison unit includes a difference making subunit and a phase comparison subunit; The subtracting subunit is connected to the pulse detection unit, the pulse coupling module and the phase comparison subunit, and is used to subtract the real-time pulse signal in the pulse signal output by the pulse coupling module from the received second detection signal, and output the reflected signal to the phase comparison subunit; The phase comparison subunit is connected to the pulse coupling module and the main control module, and is used to perform time delay control on the pulse signal output by the pulse coupling module, obtain the initial pulse signal in the pulse signal, and perform phase comparison between the initial pulse signal and the received reflected signal, and output the phase difference feedback signal to the main control module.

5. The relay adhesion detection circuit according to claim 3, characterized in that: The pulse coupling module includes a filtering unit, a power amplifier unit and a coupling unit; The filtering unit is connected to the main control module and the power amplifier unit, and is used to receive the pulse signal transmitted by the main control module, filter the received pulse signal, and output the filtered pulse signal to the power amplifier unit; The power amplifier unit is connected to the coupling unit and is used to perform gain processing on the received filtered pulse signal and output the gained pulse signal to the coupling unit; The coupling unit is connected to the AC main circuit and is used to couple the initial pulse signal in the pulse signal after receiving the gain to the AC main circuit.

6. The relay adhesion detection circuit according to claim 5, characterized in that: The coupling unit comprises a first coupling subunit and a second coupling subunit; The first coupling subunit includes a first coupling capacitor and a first switch, and is used to couple the initial pulse signal to the first AC main circuit; One end of the first coupling capacitor is connected to the first AC main circuit, and the other end is connected to one end of the first switch, and the other end of the first switch is connected to the power amplifier unit; The second coupling subunit includes a second coupling capacitor and a second switch, and is used to couple the initial pulse signal to the second AC main circuit; One end of the second coupling capacitor is connected to the second AC main circuit, and the other end is connected to one end of the second switch; the other end of the second switch is connected to the power amplifier unit; The first AC main circuit is the live circuit of the relay; the second AC main circuit is the neutral circuit of the relay; The coupling subunit includes a third coupling capacitor and a fourth coupling capacitor; One end of the third coupling capacitor is connected to the first AC main circuit, and the other end of the third coupling capacitor is connected to the filter subunit, and the third coupling capacitor is used to collect the first detection signal in the first AC main circuit; One end of the fourth coupling capacitor is connected to the second AC main circuit, and the other end of the fourth coupling capacitor is connected to the filter subunit. The fourth coupling capacitor is used to collect the first detection signal in the second AC main circuit.

7. A relay adhesion detection method, applied to the relay adhesion detection circuit according to any one of claims 1 to 6, characterized in that: The method comprises: The main control module transmits a pulse signal to the pulse coupling module; The pulse coupling module couples the initial pulse signal in the received pulse signal to the AC main circuit of the relay; The pulse detection module collects the first detection signal in the AC main circuit, processes the collected first detection signal to obtain a reflected signal, performs phase comparison between the initial pulse signal and the reflected signal, and outputs a phase difference feedback signal to the main control module; the first detection signal is a superposition signal of the initial pulse signal and the reflected signal; the reflected signal is a signal of the initial pulse signal reflected at a breakpoint of the line; The main control module determines whether the relay is stuck based on the received phase difference feedback signal sent back by the pulse detection module and a preset value.

8. The relay adhesion detection method according to claim 7, characterized in that: Before the main control module determines whether the relay is stuck based on the received phase difference feedback signal sent back by the pulse detection module and a preset value, the method further includes: The preset value is determined based on the transmission distance of the initial pulse signal in the AC circuit, the length of the gun line of the charging pile where the relay is located, and the parameters of the line in the AC main circuit.

9. The relay adhesion detection method according to claim 8, characterized in that: The determining of the preset value comprises: Determining the transmission speed of the initial pulse signal in the line based on the relative dielectric constant of the line of the AC main circuit; Determining the wavelength of the initial pulse signal based on the transmission speed of the initial pulse signal in the line and the frequency of the initial pulse signal; Determining a set first value based on the wavelength of the initial pulse signal and a first transmission distance of the initial pulse signal in the AC circuit; The second value is determined based on the wavelength of the initial pulse signal and the sum of the first transmission distance and the gun line length.

10. The relay adhesion detection method according to claim 9, characterized in that: The main control module determines whether the relay is stuck based on the received phase difference feedback signal sent back by the pulse detection module and a preset value, including: When the phase difference feedback signal received from the pulse detection module is equal to the set first value, the main control module determines that the relay is not stuck; The main control module determines that the relay is stuck when the phase difference feedback signal received and sent back by the pulse detection module is equal to the set second value.

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