Alternating current contactor health monitoring device

Abstract

The invention provides an AC contactor health monitoring device, and relates to the field of aircraft power supply systems, and the device comprises an acquisition module which comprises a DSP data processing circuit and is used for acquiring 28.5 V / suspension discrete magnitude signals sent after a contactor is connected, converting the 28.5 V / suspension discrete magnitude signals into 3.3 V / 0V digital signals, and sending the 3.3 V / 0V digital signals to the DSP data processing circuit; the mutual inductor module is used for sensing a current analog signal of a main contact of the contactor, scaling down the current analog signal according to a proportion, converting the current analog signal into current analog quantity data through analog-to-digital conversion, and sending the current analog quantity data to the DSP data processing circuit; and the DSP data processing circuit judges the health state of the contactor according to the digital signal and the current analog quantity data. By recording the power supply information and the use state of the contactor and estimating the service life of the contactor, the purposes of monitoring at any time, timely maintenance and timely replacement are achieved, and the use safety of an aircraft power supply system is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft power supply systems, and in particular to an AC contactor health monitoring device. Background Art

[0002] Electromagnetic AC contactors are widely used in aircraft AC power supply systems due to their simple working principle and strong environmental adaptability. As a switching device, the AC contactor will attract the electromagnet when the coil is energized and release the electromagnet when the coil is de-energized. The contacts will bounce to varying degrees during the closing / opening process, which will cause arc problems. Especially when the load power is large, the instantaneous starting current of the contacts opening and closing can reach more than 10 times that of the AC contactor. The arc generated in this case will cause serious erosion to the mechanical contacts of the AC contactor, reduce the electrical life, and reduce the reliability of the power supply system. At the same time, the power spike surge generated during the switching process will also cause electromagnetic interference to other airborne equipment, affecting the flight safety of the aircraft.

[0003] Although there are many new contactors with higher reliability on the market, such as intelligent AC contactors, AC solid-state contactors, etc., due to the large initial usage and wide coverage of electromagnetic AC contactors, if they are completely replaced with new contactors, the cost will be too high and it will easily cause waste of resources. Summary of the invention

[0004] In view of the fact that electromagnetic AC relays are easily damaged and have a short lifespan, and the replacement cost is too high, an embodiment of the present application provides an AC contactor health monitoring device. By monitoring the status of the contactor, recording the power supply information and usage status of the contactor, and estimating the life of the contactor, the purpose of monitoring at any time, timely maintenance, and timely replacement can be achieved, which can be used to ensure the safe use of the aircraft power supply system.

[0005] The embodiment of the present application provides the following technical solution: an AC contactor health monitoring device, comprising:

[0006] An acquisition module, wherein the acquisition module includes a DSP data processing circuit, and the acquisition module is connected to a contactor in an AC power supply circuit of the aircraft, and is used to acquire a 28.5V / suspended discrete quantity signal sent after the contactor is turned on, and convert the discrete quantity signal into a 3.3V / 0V digital signal, and then send it to the DSP data processing circuit;

[0007] A transformer module, the input end of which is connected to a contactor in an aircraft AC power supply circuit, and is used to sense the current analog signal of the main contact of the contactor; the output end of the transformer is connected to the acquisition module, and is used to scale down the current analog signal, and then send it to the DSP data processing circuit after converting it into current analog data through analog-to-digital conversion; so that the DSP data processing circuit judges the health status of the contactor according to the digital signal and current analog data of the contactor.

[0008] According to an embodiment of the present application, the acquisition module also includes an input discrete quantity acquisition circuit and an input analog quantity acquisition circuit. The input discrete quantity acquisition circuit acquires the 28.5V / suspended discrete quantity signal sent after the contactor is turned on, and converts the discrete quantity signal into a 3.3V / 0V digital signal before sending it to the DSP data processing circuit; the input analog quantity acquisition circuit is connected to the transformer module to receive the current analog signal sensed by the transformer module, and scales down the current analog signal, and then sends it to the DSP data processing circuit after converting it into current analog quantity data through analog-to-digital conversion.

[0009] According to an embodiment of the present application, the acquisition module also includes a data storage circuit, and the DSP data processing circuit is connected to the data storage circuit for storing specified data in the acquired data into the data storage circuit.

[0010] According to one embodiment of the present application, the acquisition module also includes an input loopback self-test circuit, the input end of the input loopback self-test circuit is connected to the DSP data processing circuit, and the output end of the input loopback self-test circuit is connected to the input discrete quantity acquisition circuit, which is used to introduce the 28.5V self-test power supply signal inside the acquisition module into the input discrete quantity acquisition circuit under the control of the DSP data processing circuit to complete the input loopback self-test function.

[0011] According to one embodiment of the present application, the acquisition module also includes an RS422 serial communication circuit, and the DSP data processing circuit is connected to an external onboard acquisition system through the RS422 serial communication circuit, so as to report the health status judgment result of the contactor to the onboard acquisition system.

[0012] According to one embodiment of the present application, the device also includes a power supply module, and the acquisition module also includes a DC / DC power conversion circuit. The power supply module is connected to the DC / DC power conversion circuit. The power supply module receives a 28.5V power supply from the machine, generates a 5VDC working power supply after processing and conversion, and then powers the acquisition module after passing through the DC / DC power conversion circuit.

[0013] According to one embodiment of the present application, the power supply module includes a power supply filter circuit, an overvoltage and undervoltage protection circuit, and a voltage conversion circuit connected in sequence, the power supply filter circuit is used to filter the 28.5V power supply on the machine, the overvoltage and undervoltage protection circuit is used to perform overvoltage and undervoltage protection on the input power supply, and the voltage conversion circuit is used to generate a 5VDC working power supply after voltage conversion and output it.

[0014] According to an embodiment of the present application, the DSP data processing circuit determines the switch-on times and overload-on times of the contactor based on the digital signal and current analog data of the contactor to determine the health status of the contactor.

[0015] Most of the current aircraft AC power supply systems use electromagnetic AC contactors for power supply control, but the electromagnetic AC contactors do not have functions such as status reporting and self-testing, and the wear state of the contactor contacts is uncontrollable, which easily affects the flight safety of the aircraft. In the embodiment of the present invention, a health monitoring device is installed while the layout of the original aircraft power supply system remains unchanged, which is used to collect and record the power supply information and usage status of multiple contactors and estimate the life of the contactors, so as to achieve the purpose of timely monitoring, timely maintenance, and timely replacement, and can be used to ensure the safety of the aircraft AC power supply system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 is a principle block diagram of an AC contactor health monitoring device according to an embodiment of the present invention;

[0018] Figure 2 is a cross-linking block diagram of a collection module in an AC contactor health monitoring device according to an embodiment of the present invention;

[0019] Figure 3 is a principle block diagram of a transformer module in an AC contactor health monitoring device according to an embodiment of the present invention;

[0020] Figure 4 is a principle block diagram of a power module in an AC contactor health monitoring device according to an embodiment of the present invention;

[0021] Figure 5 It is a judgment logic flow chart of the AC contactor health monitoring device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0023] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0024] like Figure 1 As shown, an embodiment of the present invention provides an AC contactor health monitoring device, comprising:

[0025] An acquisition module, wherein the acquisition module includes a DSP data processing circuit, and the acquisition module is connected to a contactor in an AC power supply circuit of the aircraft, and is used to acquire a 28.5V / suspended discrete quantity signal sent after the contactor is turned on, and convert the discrete quantity signal into a 3.3V / 0V digital signal, and then send it to the DSP data processing circuit;

[0026] A transformer module, the input end of which is connected to a contactor in an aircraft AC power supply circuit, and is used to sense the current analog signal of the main contact of the contactor; the output end of the transformer is connected to the acquisition module, and is used to scale down the current analog signal, and then send it to the DSP data processing circuit after converting it into current analog data through analog-to-digital conversion; so that the DSP data processing circuit judges the health status of the contactor according to the digital signal and current analog data of the contactor.

[0027] The embodiment of the present invention is mainly used to collect, record and analyze the use status and information of AC contactors in the aircraft AC power supply system, evaluate the service life of each key contactor in the aircraft AC power supply system, and collect the use information of the contactors and report it to the collection system, so that the system can query the use status of each contactor at any time, so as to achieve the purpose of timely monitoring, timely maintenance and timely replacement, and can be used to ensure the safe use of the aircraft AC power supply system.

[0028] In one implementation of the embodiment of the present invention, the acquisition module also includes an input discrete quantity acquisition circuit and an input analog quantity acquisition circuit. The input discrete quantity acquisition circuit acquires the 28.5V / suspended discrete quantity signal sent after the contactor is turned on, and converts the discrete quantity signal into a 3.3V / 0V digital signal, and then sends it to the DSP data processing circuit; the input analog quantity acquisition circuit is connected to the mutual inductor module, and is used to receive the current analog signal sensed by the mutual inductor module, and scales down the current analog signal, and then sends it to the DSP data processing circuit after converting it into current analog quantity data through analog-to-digital conversion.

[0029] In an implementation of the embodiment of the present invention, the acquisition module also includes a data storage circuit, and the DSP data processing circuit is connected to the data storage circuit to store specified data in the acquired data into the data storage circuit.

[0030] In an implementation manner of the embodiment of the present invention, the acquisition module also includes an input loop self-test circuit, the input end of the input loop self-test circuit is connected to the DSP data processing circuit, and the output end of the input loop self-test circuit is connected to the input discrete quantity acquisition circuit, which is used to introduce the 28.5V self-test power supply signal inside the acquisition module into the input discrete quantity acquisition circuit under the control of the DSP data processing circuit to complete the input loop self-test function.

[0031] In one implementation of the embodiment of the present invention, the acquisition module also includes an RS422 serial communication circuit, and the DSP data processing circuit is connected to an external on-board acquisition system through the RS422 serial communication circuit, so as to report the health status judgment result of the contactor to the on-board acquisition system.

[0032] In one implementation of the embodiment of the present invention, the device also includes a power supply module, and the acquisition module also includes a DC / DC power conversion circuit. The power supply module is connected to the DC / DC power conversion circuit. The power supply module receives a 28.5V power supply from the machine, generates a 5VDC working power supply after processing and conversion, and then powers the acquisition module after passing through the DC / DC power conversion circuit.

[0033] In one implementation of an embodiment of the present invention, the power module includes a power supply filter circuit, an overvoltage and undervoltage protection circuit, and a voltage conversion circuit connected in sequence, the power supply filter circuit is used to filter the 28.5V power supply on the machine, the overvoltage and undervoltage protection circuit is used to perform overvoltage and undervoltage protection on the input power supply, and the voltage conversion circuit is used to generate a 5VDC working power supply after voltage conversion and output it.

[0034] In an implementation of the embodiment of the present invention, the DSP data processing circuit determines the switch-on times and overload-on times of the contactor according to the digital signal and current analog data of the contactor to determine the health status of the contactor.

[0035] During specific implementation, the hardware of the AC contactor health monitoring device is mainly composed of structural parts, connectors, acquisition modules, power modules and transformer modules. The circuit is mainly composed of transformers, sampling circuits, operational amplifier circuits, data processing circuits and other circuits. First, the transformer is connected to the original AC power supply circuit, and then the secondary current induced by the transformer is converted into a sampling voltage through a sampling resistor. The sampling voltage is then proportionally reduced by an operational amplifier and sent to the AD module of the DSP for analog-to-digital conversion, thereby obtaining the use information of the contactor. The contactor health monitoring equipment determines the service life of each key contactor in the power supply system by collecting and recording the number of switching times, overload times and connected current information of the contactor. By collecting and reporting the use information of the AC contactor to the superior system, the superior system can query the use of each AC contactor at any time, so as to achieve the purpose of monitoring at any time, timely maintenance and timely replacement, and ensure the safe use of the power supply system.

[0036] The principle block diagram of the AC contactor health monitoring device according to the embodiment of the present invention is as follows: Figure 1 As shown. After the contactor is turned on, the acquisition module receives the 28.5V / suspended discrete quantity signal sent by the contactor, and after entering the discrete quantity processing circuit, it is converted into a 3.3V / 0V digital signal; the DSP main control circuit collects these 3.3V / 0V digital signals, performs logic judgment on the chip, and then scales down the analog signal to 0~3V through the sampling resistor and amplifier in the input analog quantity acquisition circuit, and then converts it into analog data through the on-chip A / D module of the DSP chip or the off-chip A / D module, and transmits the data to the DSP data processing circuit to complete the current data acquisition. After the DSP data processing circuit processes the collected current data, according to the fault judgment conditions, the current data results are stored in the memory, and reported to the on-board acquisition system through the RS422 bus communication interface, or the stored data is modified by the received information. When the input discrete quantity processing circuit loopback self-test is performed, the DSP main control circuit controls the electronic contacts at the output end of the optical MOS relay in the input loopback self-test circuit to close, thereby introducing the 28.5V self-test power supply into the input discrete quantity processing circuit to complete the loopback detection of the input discrete quantity processing circuit. The DC / DC power conversion circuit in this embodiment uses a domestic DC / DC power supply chip to provide +1.9V and +3.3V power supplies for the relevant functional circuits of the acquisition module.

[0037] The acquisition module of the embodiment of the present invention is mainly composed of a DSP data processing circuit, a data storage circuit, an input discrete quantity acquisition circuit, an input analog quantity acquisition circuit, an input loopback self-test circuit, an RS422 serial port communication circuit and a DC / DC power supply conversion circuit. The discrete quantity signal input to the acquisition module by the external contactor is first processed by the input discrete quantity acquisition circuit. The DSP data processing circuit collects the processed signal and generates acquisition logic on the chip. Then, the analog quantity signal of the corresponding channel is collected by the input analog quantity acquisition circuit and converted into analog quantity data to complete the acquisition function. The DSP main control circuit controls the input loopback self-test circuit to introduce the 28.5V signal inside the acquisition module into the input discrete quantity acquisition circuit to complete the input loopback self-test function. The DSP data processing circuit analyzes the collected data according to the fault judgment conditions and stores the specified data into the storage circuit, and at the same time sends the fault information to the outside through the RS422 circuit. The cross-linking block diagram of the acquisition module is shown as follows. Figure 2 shown.

[0038] The transformer module of the embodiment of the present invention is composed of a high-precision AC transformer. The transformer selected in this embodiment is a through-core structure. The current signal passing through the transformer can be reduced to a small current signal at a ratio of 1:1000 by the electromagnetic induction principle without damaging the line, and input into the data processing circuit. Figure 3 shown.

[0039] The power module of the embodiment of the present invention is composed of functional circuits such as a power filter circuit, an overvoltage and undervoltage protection circuit, and a voltage conversion circuit. The power module receives a 28.5V power supply from the machine and is connected to the filter circuit. The filter circuit suppresses the high-frequency interference signal introduced by the input power supply, and at the same time suppresses the noise generated inside the main contactor acquisition recorder from being transmitted through the power line. The overvoltage and undervoltage protection circuit is composed of a surge suppression circuit and an energy storage circuit, which ensures the normal operation of the main contactor acquisition recorder when an overvoltage surge, undervoltage surge, or power interruption occurs in the input power supply. After the input power passes through the filter circuit, the anti-reverse connection circuit, the switch control circuit, and the undervoltage and overvoltage protection circuit, a 28.5V power supply is output for discrete quantity drive. The voltage conversion circuit is mainly composed of a DC / DC converter to generate a 5VDC working power supply. The working state of the voltage conversion circuit in the power conversion module is monitored by the acquisition module. When the functional module works abnormally, a fault signal is issued to facilitate fault detection and isolation. The power module principle block diagram is shown as follows Figure 4 shown.

[0040] Combined with the AC contactor manufacturer's product manual and the historical application information of this type of device, confirm the software judgment process as follows Figure 5 shown.

[0041] When the monitoring device detects that the contactor switch is effective, the contactor current is greater than 2A and does not exceed the rated current of 20A and the duration exceeds 200ms, the contactor is judged to be in the "normal" state, and the normal connection times are increased by 1; when the monitoring device detects that the contactor switch is effective, the contactor current is greater than the rated current of 20A and the duration exceeds 200ms, the contactor is judged to be in the "overload" state, and the overload connection times are increased by 1; when the contactor normal connection times are greater than or equal to 22,000 times or the overload connection times are greater than or equal to 50 times, the "attention" command will be reported to the superior system through the RS422 bus. At this time, the contactor needs to be repaired or replaced, as shown in Table 1.

[0042] Table 1 Contactor status determination conditions

[0043]

[0044] The health monitoring device of the embodiment of the present invention is used to collect the control signal and main contact working current of the contactor in the aircraft AC power supply system, and record the working times and usage status of the contactor. The name, factory number, normal connection times, overload connection times, and overload connection status of each contactor are reported to the aircraft data acquisition system through the RS422 digital bus, and the information of each contactor can be edited, displayed, replaced, and cleared through the RS422 digital bus. Through the upper computer software, the usage status and historical connection times of each contactor can be clearly seen, and the state of the contactor can be judged by the connection times and the current size when connected. At the same time, the contactor number, name, and historical connection times can be written into the memory through the software for easy access at any time.

[0045] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. An AC contactor health monitoring device, characterized in that: include: An acquisition module, wherein the acquisition module includes a DSP data processing circuit, and the acquisition module is connected to a contactor in an AC power supply circuit of the aircraft, and is used to acquire a 28.5V / suspended discrete quantity signal sent after the contactor is turned on, and convert the discrete quantity signal into a 3.3V / 0V digital signal, and then send it to the DSP data processing circuit; A transformer module, the input end of which is connected to a contactor in an aircraft AC power supply circuit, and is used to sense the current analog signal of the main contact of the contactor; the output end of the transformer is connected to the acquisition module, and is used to scale down the current analog signal, and then send it to the DSP data processing circuit after converting it into current analog data through analog-to-digital conversion; so that the DSP data processing circuit judges the health status of the contactor according to the digital signal and current analog data of the contactor.

2. The AC contactor health monitoring device according to claim 1, characterized in that: The acquisition module also includes an input discrete quantity acquisition circuit and an input analog quantity acquisition circuit. The input discrete quantity acquisition circuit acquires the 28.5V / suspended discrete quantity signal sent after the contactor is turned on, converts the discrete quantity signal into a 3.3V / 0V digital signal, and then sends it to the DSP data processing circuit; the input analog quantity acquisition circuit is connected to the mutual inductor module, and is used to receive the current analog signal sensed by the mutual inductor module, and scales down the current analog signal, and then sends it to the DSP data processing circuit after converting it into current analog quantity data through analog-to-digital conversion.

3. The AC contactor health monitoring device according to claim 1, characterized in that: The acquisition module also includes a data storage circuit, and the DSP data processing circuit is connected to the data storage circuit for storing designated data in the acquired data into the data storage circuit.

4. The AC contactor health monitoring device according to claim 2, characterized in that: The acquisition module also includes an input loop self-test circuit, the input end of the input loop self-test circuit is connected to the DSP data processing circuit, and the output end of the input loop self-test circuit is connected to the input discrete quantity acquisition circuit, which is used to introduce the 28.5V self-test power supply signal inside the acquisition module into the input discrete quantity acquisition circuit under the control of the DSP data processing circuit to complete the input loop self-test function.

5. The AC contactor health monitoring device according to claim 1, characterized in that: The acquisition module also includes an RS422 serial communication circuit, and the DSP data processing circuit is connected to an external on-board acquisition system through the RS422 serial communication circuit, so as to report the health status judgment result of the contactor to the on-board acquisition system.

6. The AC contactor health monitoring device according to claim 1, characterized in that: The device also includes a power supply module, and the acquisition module also includes a DC / DC power conversion circuit. The power supply module is connected to the DC / DC power conversion circuit. The power supply module receives a 28.5V power supply from the machine, generates a 5VDC working power supply after processing and conversion, and then powers the acquisition module after passing through the DC / DC power conversion circuit.

7. The AC contactor health monitoring device according to claim 6, characterized in that: The power module includes a power filter circuit, an overvoltage and undervoltage protection circuit, and a voltage conversion circuit connected in sequence. The power filter circuit is used to filter the 28.5V power supply on the machine, the overvoltage and undervoltage protection circuit is used to perform overvoltage and undervoltage protection on the input power supply, and the voltage conversion circuit is used to generate a 5VDC working power supply after voltage conversion and output it.

8. The AC contactor health monitoring device according to claim 1, characterized in that: The DSP data processing circuit determines the switch-on times and overload-on times of the contactor according to the digital signal and current analog data of the contactor, so as to determine the health status of the contactor.

Images