A fault diagnosis method for unmanned ship integrated intelligent variable frequency permanent magnet driving device

Abstract

This invention discloses a fault diagnosis method for an integrated intelligent variable frequency permanent magnet drive device for unmanned surface vessels (USVs). Based on an intelligent frequency converter and a permanent magnet propulsion motor, the method first categorizes and summarizes the possible fault and alarm information of the propulsion motor system according to the equipment location. Then, it analyzes the correlation between the fault and alarm information, classifies them, and formulates fault handling methods adapted to the fault levels. Combined with the unit's operating logic, it formulates corresponding fault alarm handling logic. This provides a reference for unmanned drive devices with high requirements for drive device size and strict requirements for autonomous fault alarm diagnosis and handling control strategies. At the same time, it provides good economic benefits and social value for the USV industry.

Description

Technical Field

[0001] This invention belongs to the field of unmanned surface vessel (USV) technology, specifically relating to a fault diagnosis method for an integrated intelligent variable frequency permanent magnet drive device for USVs, which is particularly suitable for USVs with requirements for low vibration and noise and autonomous fault diagnosis. Background Technology

[0002] Unmanned surface vessels (USVs) are unmanned, intelligent combat platforms that navigate underwater autonomously via remote control. Due to their unmanned design, USVs eliminate the risk of personnel casualties during wartime. They can perform tasks such as firepower strikes, underwater obstacle breaching, close-range reconnaissance and patrol, equipment and supply transport, and emergency rescue in high-risk environments including heavily defended enemy positions, complex hydrological and meteorological conditions, and biological and chemical radiation exposure.

[0003] Unmanned surface vessels (USVs) typically connect to shore-based base stations via intelligent modules. These base stations serve as the command and control center for the entire propulsion system, responsible for mission planning, intelligent decision-making, status monitoring, and command and control of the USVs. USVs often operate in complex and variable water environments, frequently encountering unpredictable influences.

[0004] As the operational capabilities of unmanned surface vessels (USVs) improve, their complexity also increases, and safety assurance receives further in-depth attention. Among these, it is particularly important to detect potential faults in USVs as early as possible, reduce potential risks, and achieve autonomous fault alarm diagnosis and fault-tolerant control. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a fault diagnosis method for an integrated intelligent variable frequency permanent magnet drive device for unmanned surface vessels (USVs). The aim is to reduce the overall size of the USV drive device, making its structure very compact, improving the vibration and noise of the permanent magnet propulsion motor, facilitating maintenance, and increasing the rigidity of the propulsion motor. This provides a reference for USV drive devices with high requirements for drive device size and strict requirements for autonomous fault alarm diagnosis and handling control strategies, while also providing good economic and social benefits to the USV industry.

[0006] The technical solution adopted by this invention to solve its technical problem is: a fault diagnosis method for an integrated intelligent variable frequency permanent magnet drive device for unmanned surface vessels, based on an intelligent variable frequency permanent magnet drive device including a permanent magnet propulsion motor and an intelligent frequency converter connected above the permanent magnet propulsion motor, as well as a control cabinet, an external water supply system, and an oil supply system. The permanent magnet propulsion motor includes a stator, a rotor, an end cover, and a concave end cover bearing; the intelligent frequency converter includes a controller arranged in front and behind, a water-air heat exchanger, a support capacitor, a fuse micro switch, and a power module located in the AC inverter output area. An optical fiber is led out from below the power module. It also includes a cooling-control-inlet area parallel to the controller, a DC filter area located below the water-air heat exchanger, and an outlet area located below the power module; including the following steps:

[0007] S1, classify and summarize the fault information and alarm information that may occur in the propulsion motor system according to the equipment location.

[0008] The fault information of the intelligent frequency converter is divided into: output phase current hardware overcurrent fault, output phase current software overcurrent fault, bus voltage software overvoltage fault, bus voltage hardware overvoltage fault, bus voltage software undervoltage fault, frequency converter internal output reactor winding overtemperature fault, input reactor winding overtemperature fault, inverter module heat sink plate overtemperature fault, power module reverse current heat sink plate overtemperature fault, fiber optic feedback fault, pre-charge fault, output fuse fault, and control unit power failure fault; the alarm information of the intelligent frequency converter is divided into: output reactor winding overtemperature alarm, input reactor winding overtemperature alarm, DC bus overvoltage alarm, DC bus undervoltage alarm, inverter module heat sink plate overtemperature alarm, power module reverse current heat sink plate overtemperature alarm, and intelligent frequency converter air temperature too high alarm.

[0009] The fault information of permanent magnet propulsion motors is divided into stator winding over-temperature fault, stator winding end over-temperature fault, bearing over-temperature fault, and bearing bush over-temperature fault; the alarm information of permanent magnet propulsion motors is divided into stator winding over-temperature alarm, stator winding end over-temperature alarm, bearing over-temperature alarm, bearing bush over-temperature alarm, and water accumulation alarm.

[0010] The fault information of the control cabinet is divided into DC forward overcurrent fault, DC reverse overcurrent fault, circuit breaker tripping fault, external emergency stop fault, external CAN communication fault and internal CAN communication fault; the alarm information of the control cabinet is divided into internal CAN communication alarm, internal Ethernet communication alarm, external CAN communication alarm and external Ethernet communication alarm.

[0011] The fault information of the water supply system is divided into inlet water over-temperature fault, inlet and outlet water pressure difference over-pressure fault, and inlet water pressure fault; the alarm information of the water supply system is divided into inlet water over-temperature alarm, inlet water pressure difference alarm, and inlet water pressure alarm.

[0012] The fault information of the oil supply system is divided into four categories: high lubricating oil temperature, high lubricating oil pressure differential, high lubricating oil pressure, and low lubricating oil pressure.

[0013] S2 analyzes fault information that may cause serious damage to the permanent magnet drive device, and analyzes the correlation between fault information and alarm information to prevent the triggering of a higher-level handling method due to the unreliability of the temperature sensor.

[0014] S3 classifies all fault and alarm information according to their severity from high to low and formulates corresponding fault handling methods: For Level 1 faults, the alarm handling measure is for the entire machine to enter a fault state and the circuit breaker to open; if the fault disappears, it can only enter a shutdown state after resetting; for Level 2 faults, the alarm handling measure is for the permanent magnet drive unit to switch to standby mode, and the fault information will be automatically cleared after communication is restored; for Level 3 faults, the alarm handling measure is to report the fault information to the navigation control system and request a shutdown to check the water supply system; for Level 4 faults, the alarm handling measure is for the permanent magnet drive unit to switch to a fault state, and automatically restart after a delay; if the fault is not reset... If the fault is reset, the system will return to fault status and power will be disconnected. If the fault is reset, normal operation will resume. For level 5 faults, the fault alarm handling measure is to stop the faulty branch and continue to operate the non-faulty branches, i.e., single branch operation. For level 6 faults, the fault alarm handling measure is to send a fault message to the superior system when the water supply system data reaches the fault threshold and request a reduction to the minimum speed of the permanent magnet propulsion motor. If the superior system does not respond to the reduction request within a specified time, the speed will be automatically reduced. For level 7 faults, the fault alarm handling measure is for the permanent magnet drive device to request a reduction in speed from the overall system. If there is no response within a specified time, the speed will be automatically reduced, and the system will resume operation after the alarm disappears. For level 8 faults, the fault alarm handling measure is for the permanent magnet drive device to maintain its pre-alarm operating state.

[0015] S4, combined with the operating logic of the permanent magnet drive device, formulates corresponding fault alarm handling logic, and implements it through code, ultimately completing the design of relevant fault protection and control strategies.

[0016] The fault diagnosis method for an integrated intelligent variable frequency permanent magnet drive device for unmanned surface vessels, wherein the first-level faults in step S3 include: an inlet water overheating fault when the inlet water temperature exceeds the fault threshold and the inverter module heat sink plate temperature exceeds the alarm threshold; an inlet water pressure difference fault when the inlet water pressure difference exceeds the fault threshold and the inverter module heat sink plate temperature exceeds the alarm threshold; an overheating fault when the lubricating oil temperature is higher than the fault threshold and the bearing bush temperature is higher than the fault threshold; an overheating fault when the bearing bush temperature is higher than the fault threshold; a control unit fault when a control unit malfunctions; and an emergency stop fault when an emergency stop command is received.

[0017] The fault diagnosis method for an integrated intelligent variable frequency permanent magnet drive device for unmanned surface vessels includes the following secondary faults in step S3: external CAN communication is judged as an external CAN communication fault when all external CAN communication is interrupted for 10 seconds; internal CAN communication is judged as an internal CAN communication fault when all internal CAN communication alarms are triggered.

[0018] The fault diagnosis method for an integrated intelligent variable frequency permanent magnet drive device for unmanned surface vessels includes three levels of faults in step S3: when the inlet water pressure exceeds the fault threshold, it is judged as an inlet water pressure fault; when the oil pressure difference exceeds the fault threshold, it is judged as a lubricating oil pressure difference fault; when the oil pressure high pressure exceeds the fault threshold, it is judged as a lubricating oil pressure high pressure fault; and when the oil pressure low pressure is lower than the fault threshold, it is judged as a lubricating oil pressure low pressure fault.

[0019] The fault diagnosis method for an integrated intelligent variable frequency permanent magnet drive device for unmanned surface vessels includes the following four levels of faults in step S3: when the phase current amplitude of one phase in both branches of the permanent magnet propulsion motor is greater than the fault threshold, it is judged as a software overcurrent fault of the phase current of the two branches; when the bus voltage of one phase in both branches of the permanent magnet propulsion motor is less than the fault threshold, it is judged as a software undervoltage fault of the bus voltage of the two branches.

[0020] The fault diagnosis method for an integrated intelligent variable frequency permanent magnet drive device for unmanned surface vessels, wherein the five levels of faults in step S3 include: a stator winding temperature exceeding a fault threshold is judged as a winding over-temperature fault; a bus voltage exceeding a fault threshold is judged as a bus voltage software overvoltage fault; a bus voltage exceeding a fault threshold is judged as a bus voltage hardware overvoltage fault; a phase current amplitude exceeding a fault threshold is judged as a phase current hardware overcurrent fault; a branch phase current amplitude exceeding a fault threshold is judged as a phase current software overcurrent fault; a branch bus voltage less than a fault threshold is judged as a bus voltage software undervoltage fault; an input current exceeding a fault threshold is judged as a DC forward overcurrent fault; and a reverse current exceeding a fault threshold is judged as a DC... Reverse overcurrent fault; circuit breaker tripping abnormally is judged as a circuit breaker tripping fault; inverter module heat sink base plate overheating fault exceeding the fault threshold is judged as an inverter module heat sink base plate overheating fault; power module reverse current heat sink base plate overheating fault exceeding the fault threshold is judged as a power module reverse current heat sink base plate overheating fault; during pre-charging, if the supporting capacitor voltage does not reach the preset value within a predetermined time, it is judged as a pre-charging fault; if it exceeds the input reactor overheating fault threshold, it is judged as an input reactor winding overheating fault; if it exceeds the output reactor overheating fault threshold, it is judged as an output reactor winding overheating fault; when the fuse microswitch is open, it is judged as an output fuse fault; when there is no light in the fiber optic feedback and the hardware gives fault information, it is judged as a fiber optic feedback fault.

[0021] The fault diagnosis method for an integrated intelligent variable frequency permanent magnet drive device for unmanned surface vessels includes six levels of faults in step S3: when the inlet water temperature exceeds the fault threshold, it is judged as an inlet water over-temperature level two fault; when the inlet water pressure difference is less than the fault threshold, it is judged as an inlet and outlet water pressure difference level two fault.

[0022] The fault diagnosis method for an integrated intelligent variable frequency permanent magnet drive device for unmanned surface vessels, wherein the seven levels of faults in step S3 include: an inlet water temperature exceeding the alarm threshold is judged as an inlet water over-temperature alarm; an inlet water pressure difference exceeding the alarm threshold is judged as an inlet water pressure difference alarm; a stator winding temperature exceeding the alarm threshold is judged as a winding over-temperature alarm; a bearing bush temperature exceeding the alarm threshold is judged as a bearing bush over-temperature alarm; a bus voltage exceeding the alarm threshold is judged as a DC bus overvoltage alarm; and a bus voltage less than the alarm threshold is judged as a DC bus overvoltage alarm. Undervoltage alarm; inverter module heat sink plate temperature exceeding the alarm threshold is judged as inverter module heat sink plate over-temperature alarm; power module reverse current heat sink plate temperature exceeding the alarm threshold is judged as power module reverse current heat sink plate over-temperature alarm; input reactor winding temperature exceeding the alarm threshold is judged as input reactor winding over-temperature alarm; output reactor winding temperature exceeding the alarm threshold is judged as output reactor winding over-temperature alarm; water accumulation alarm IO signal is read as water accumulation alarm; inlet water pressure exceeds the alarm threshold is judged as inlet water pressure alarm.

[0023] The fault diagnosis method for an integrated intelligent variable frequency permanent magnet drive device for unmanned surface vessels includes the following eight levels of faults in step S3: a temperature exceeding the air over-temperature alarm threshold of the intelligent variable frequency drive is judged as an over-temperature alarm in the variable frequency control equipment; an internal CAN1 communication interruption for 10 seconds is judged as an internal CAN1 communication alarm; an internal CAN2 communication interruption for 10 seconds is judged as an internal CAN2 communication alarm; an Ethernet communication interruption for 10 seconds is judged as an internal Ethernet communication alarm; an external CAN communication alarm for 10 seconds is judged as an external CAN communication alarm; and an external Ethernet communication interruption for 10 seconds is judged as an external Ethernet communication fault.

[0024] The aforementioned fault diagnosis method for an integrated intelligent variable frequency permanent magnet drive device for unmanned surface vessels sets different priorities for fault alarm handling methods from low to high: Level I is fault-delayed shutdown and after successful automatic restart; Level II is alarm operation; Level III is derating to the minimum speed; Level IV is derating; Level V is branch isolation; Level VI is fault-automatic restart shutdown and reset; Level VII is fault-delayed shutdown after delay; Level VIII is fault standby; and Level IX is fault shutdown.

[0025] The beneficial effects of this invention are:

[0026] The permanent magnet drive device of this invention integrates the permanent magnet propulsion motor and intelligent frequency converter at the top. The permanent magnet propulsion motor uses a concave bearing in the end cover, with the end wire connected to the main circuit of the frequency converter. The frequency converter adopts a partitioned, layered, and block-arranged layout, reducing the overall size of the drive device, making the structure very compact, improving the vibration and noise of the permanent magnet propulsion motor, facilitating maintenance, and increasing the rigidity of the propulsion motor. Furthermore, the autonomous fault alarm diagnosis and processing mode, based on fault alarm correlation analysis, fault alarm summarization and classification, and autonomous fault alarm diagnosis and processing control strategy design, provides a reference for unmanned drive devices with high requirements for drive device size and strict requirements for autonomous fault alarm diagnosis and processing control strategies. It also provides significant economic and social value to the unmanned surface vessel industry. Attached Figure Description

[0027] Figure 1 This is a side view of the permanent magnet drive device of the present invention;

[0028] Figure 2 This is a front view of the permanent magnet drive device of the present invention;

[0029] Figure 3 This is a schematic diagram of the structure of the intelligent frequency converter of the present invention;

[0030] Figure 4 This is a schematic diagram of the permanent magnet propulsion motor of the present invention;

[0031] Figure 5 This is a comparison diagram of end cap recessed bearings and traditional pedestal bearings;

[0032] Figure 6 This is a communication network topology diagram of the present invention;

[0033] Figure 7 This is a schematic diagram of existing fault diagnosis methods;

[0034] Figure 8 Diagnostic flowchart for permanent magnet drive device under autonomous fault alarm diagnosis and handling method.

[0035] The labels for each attached diagram are as follows: 1—Intelligent frequency converter, 1.1—Cooling-control-incoming line area, 1.2—Controller, 1.3—Water-air heat exchanger, 1.4—DC filter area, 1.5—Power module, 1.6—Outgoing line area, 1.7—Support capacitor, 1.8—Fuse micro switch, 1.9—Fiber optic cable, 2—Permanent magnet propulsion motor, 2.1—Stator, 2.2—Rotor, 2.3—End cover, 2.4—End cover type bearing. Implementation

[0036] The present invention will now be described in further detail with reference to the accompanying drawings.

[0037] This invention aims to provide an integrated intelligent variable frequency permanent magnet drive device for unmanned surface vessels (USVs), offering a reference for USV drive devices with high requirements for drive device size, vibration and noise control, and stringent autonomous fault alarm diagnosis and processing control strategies. (Refer to...) Figures 1-4 As shown, in the first embodiment of the present invention, it includes an intelligent frequency converter 1 and a permanent magnet propulsion motor 2, wherein the intelligent frequency converter 1 and the permanent magnet propulsion motor 2 are integrated at the top; the permanent magnet propulsion motor 2 includes a stator 2.1, a rotor 2.2, an end cover 2.3, and a concave end cover type bearing 2.4, etc. The stator 2.1 adopts a structural design that connects to the main circuit of the intelligent frequency converter 1 by means of end-out wiring. The end cover type bearing 2.4 reduces the size of the motor bearing compared with the traditional pedestal bearing. A structural comparison diagram is shown in the attached diagram. Figure 5 This improves the overall vibration and noise of the permanent magnet propulsion motor, facilitates maintenance, and increases the rigidity and strength of the propulsion motor.

[0038] The intelligent frequency converter 1 includes a controller 1.2, a water-air heat exchanger 1.3, a supporting capacitor 1.7, a fuse micro switch 1.8, and a power module 1.5 located in the AC inverter output area, arranged sequentially. An optical fiber 1.9 leads out from below the power module 1.5. It also includes a cooling-control-inlet area 1.1 arranged alongside the controller 1.2, a DC filter area 1.4 located below the water-air heat exchanger 1.3, and an outlet area 1.6 located below the power module 1.5. The intelligent frequency converter 1 adopts a layered and block-based arrangement, which greatly reduces the size of the drive device as a whole.

[0039] The fault alarm diagnosis method of the present invention is based on the summarization and classification of fault alarms, and the design of autonomous fault diagnosis and processing control strategies. Its autonomous fault alarm diagnosis and processing mode is mainly carried out from the following steps.

[0040] S1 categorizes and summarizes the fault and alarm information that may be generated by the propulsion motor system according to the equipment location.

[0041] The fault information of intelligent frequency converter 1 is divided into the following categories: output phase current hardware overcurrent fault, output phase current software overcurrent fault, bus voltage software overvoltage fault, bus voltage hardware overvoltage fault, bus voltage software undervoltage fault, frequency converter internal output reactor winding overtemperature fault, input reactor winding overtemperature fault, inverter module heat sink plate overtemperature fault, power module reverse current heat sink plate overtemperature fault, fiber optic feedback fault, pre-charge fault, output fuse fault, and control unit power failure fault. The alarm information of intelligent frequency converter 1 is divided into the following categories: output reactor winding overtemperature alarm, input reactor winding overtemperature alarm, DC bus overvoltage alarm, DC bus undervoltage alarm, inverter module heat sink plate overtemperature alarm, power module reverse current heat sink plate overtemperature alarm, and intelligent frequency converter 1 control equipment air temperature too high alarm.

[0042] The fault information of the permanent magnet propulsion motor 2 is divided into stator winding over-temperature fault, stator winding end over-temperature fault, bearing over-temperature fault, and bearing bush (radial bush and thrust bush) over-temperature fault; the alarm information of the permanent magnet propulsion motor 2 is divided into stator winding over-temperature alarm, stator winding end over-temperature alarm, bearing over-temperature alarm, bearing bush over-temperature alarm, and water accumulation alarm.

[0043] The fault information of the control cabinet is divided into DC forward overcurrent fault, DC reverse overcurrent fault (branch short circuit), circuit breaker tripping fault, external emergency stop fault, external CAN communication fault and internal CAN communication fault; the alarm information of the control cabinet is divided into internal CAN1 communication alarm, internal CAN2 communication alarm, internal Ethernet communication alarm, external CAN3 communication alarm, external CAN4 communication alarm and external Ethernet communication alarm.

[0044] The fault information of the water supply system is divided into inlet water over-temperature fault, inlet and outlet water pressure difference over-pressure fault, and inlet water pressure fault; the alarm information of the water supply system is divided into inlet water over-temperature alarm, inlet water pressure difference alarm, and inlet water pressure alarm.

[0045] The fault information of the oil supply system is divided into four categories: high lubricating oil temperature, high lubricating oil pressure difference, high lubricating oil pressure, and low lubricating oil pressure.

[0046] S2 analyzes fault information that may cause serious damage to the unit (the permanent magnet drive device consisting of the intelligent frequency converter 1, the permanent magnet propulsion motor 2, and its control cabinet), and analyzes the correlation between fault information and alarm information to prevent the triggering of a higher-level handling method due to the unreliability of the temperature sensor.

[0047] For example, serious malfunctions in the external water and oil supply systems will directly cause significant damage to the unit's end-cover bearings 2.4, bearing bushes, and power modules 1.5. In such cases, the unit should not operate for extended periods. According to fault classification, this should be categorized as the most severe fault. However, since the status information of the water and oil supply systems is monitored by external sensors, if the temperature sensors themselves are interfered with and generate false alarms, the highest-level fault handling method is no longer appropriate. In this situation, the fault information from the external water and oil supply systems should be combined with the status information from the permanent magnet propulsion motor 2 and the intelligent frequency converter 1 for judgment. Only when the external oil / water fault directly reflects an abnormal increase in the unit's internal temperature should it be classified as the most severe fault. Therefore, the inlet water overheating fault... The following are classified as Level 1 faults: overheating alarm of inverter module heat sink base plate, overheating alarm of inlet water pressure difference, and overheating alarm of lubricating oil temperature and motor bearing bush temperature. After these occur, the permanent magnet propulsion motor 2 must be powered off and shut down. If only overheating alarm of inlet water, overheating alarm of inlet water pressure difference, and overheating alarm of lubricating oil temperature occur, the motor power can be significantly reduced to ensure that the unit can continue to provide power. If these three types of conditions only trigger alarms, the motor power can be slightly reduced to ensure that the unit can continue to provide power. Apart from these three types of fault information and alarm information, other external oil and water faults do not immediately cause damage to the unit. Therefore, a delayed shutdown method is adopted to provide power for a short time so that the upper equipment can jointly handle the fault.

[0048] Regarding the hazards to the unit, damage to the propulsion motor bearings, bearing bushes, and power module 1.5 in the intelligent frequency converter 1 will cause irreversible damage to the unit. Therefore, these three types of faults must be classified as the most serious faults. Monitoring of these three types of faults can only be done directly through temperature sensors; therefore, regardless of whether the sensor reports a false alarm, the unit must be shut down immediately. For the propulsion motor system of this project, since the propulsion motor is a six-phase motor with redundant backups in the stator windings, if a phase module fails, only the faulty branch can be disconnected. Therefore, bearing bush overheating, control unit power failure, and emergency shutdown faults must be classified as first-level faults, and the unit must be shut down when such faults occur. Regarding the controllability of the unit, if communication between the unit and upper-level equipment, as well as communication between various devices within the unit, fails and there is no backup, the unit will lose control. At this time, the unit should no longer provide power. The project's communication network topology is as follows: Figure 6 As shown.

[0049] Figure 6The project displays two internal CAN channels, one internal Ethernet channel, three external CAN channels, and two external Ethernet channels. Functionally, the control involves internal CAN1 and CAN2, and external CAN3 and CAN4. CAN1 and CAN2 are backups for each other, as are CAN3 and CAN4. If CAN1 and CAN2 fail simultaneously, it is an internal CAN communication failure; if CAN3 and CAN4 fail simultaneously, it is an external CAN communication failure. If both internal and external CAN failures occur, the unit must be shut down. However, sometimes communication failures may be caused by temporary data congestion. If the problem is resolved after a period of time, the entire ship will still have power requirements. In such cases, the communication failure should be classified as a Class II failure, meaning that power output is stopped but the main power supply is not disconnected, ensuring that the unit can start quickly after communication is restored.

[0050] In addition to the faults analyzed above, for overcurrent and undervoltage faults detected by the software, if both branches fail simultaneously, the software can be automatically reset and restarted once, similar to the automatic reclosing mechanism in the power grid, to prevent recovery faults caused by intermittent electromagnetic interference. If the reset is successful, the unit will restart; if the fault persists after the reset, the unit will be shut down and the circuit breaker will be tripped. All other remaining faults involve branch redundancy, therefore only the faulty branch can be disconnected, allowing the unit to enter single-branch operation mode.

[0051] S3 classifies all fault and alarm information into categories from high to low severity and formulates fault handling methods corresponding to the fault levels.

[0052] For Class 1 faults, the fault alarm handling measure is to put the entire machine into a fault state and disconnect the branch circuit breaker; if the fault disappears, the machine can only enter the shutdown state after resetting. Class 1 faults include: when the inlet water temperature exceeds the fault threshold and the inverter module heat sink plate temperature exceeds the alarm threshold, it is judged as an inlet water overheating fault; when the inlet water pressure difference exceeds the fault threshold and the inverter module heat sink plate temperature exceeds the alarm threshold, it is judged as an inlet and outlet water pressure difference fault; when the lubricating oil temperature is higher than the fault threshold and the bearing bush temperature is higher than the fault threshold, it is judged as a lubricating oil overheating fault; when the bearing bush temperature is higher than the fault threshold, it is judged as a bearing bush overheating fault; when the control unit malfunctions, it is judged as a control unit fault; when an emergency stop command is received, it is judged as an emergency stop fault.

[0053] For Level 2 (Class) faults, the fault alarm handling measure is to switch the entire unit to standby mode for startup, and the fault information will be automatically cleared after communication is restored. Level 2 (Class) faults include: external CAN communication faults when both external CAN3 and CAN4 communication are interrupted for 10 seconds; and internal CAN communication faults when both internal CAN1 and CAN2 communication alarms are triggered.

[0054] For Level 3 (Class III) faults, the fault alarm handling procedure is to report the fault information to the navigation control system (i.e., the control system of the entire vessel) and request a shutdown to check the water supply system; if no shutdown command is received within 3 minutes, the system will automatically shut down. Level 3 (Class III) faults include: inlet water pressure exceeding the fault threshold is considered an inlet water pressure fault; oil pressure differential exceeding the fault threshold is considered a lubricating oil pressure differential fault; high oil pressure exceeding the fault threshold is considered a lubricating oil high pressure fault; and low oil pressure below the fault threshold is considered a lubricating oil low pressure fault.

[0055] For Level 4 (Class) faults, the fault alarm handling measures are as follows: the entire unit switches to fault state, automatically restarts after a delay, and if the fault is not reset, it switches back to fault state and disconnects the power supply; if the fault is reset, it resumes normal operation. Level 4 (Class) faults include: when the phase current amplitude of one phase in both branches of the permanent magnet propulsion motor 2 exceeds the fault threshold, it is judged as a software overcurrent fault in the phase current of two branches; when the bus voltage of one phase in both branches of the permanent magnet propulsion motor 2 is less than the fault threshold, it is judged as a software undervoltage fault in the bus voltage of two branches.

[0056] For Level 5 (Class) faults, the fault alarm handling measure is to shut down the branch where the fault occurred, while the branches without faults continue to operate, i.e., single-branch operation. Level 5 (Class) faults include: stator winding temperature exceeding the fault threshold is judged as winding over-temperature fault; bus voltage exceeding the fault threshold is judged as bus voltage software overvoltage fault; bus voltage exceeding the fault threshold is judged as bus voltage hardware overvoltage fault; phase current amplitude exceeding the fault threshold is judged as phase current hardware overcurrent fault; phase current amplitude of a certain branch exceeding the fault threshold is judged as phase current software overcurrent fault; bus voltage of a certain branch less than the fault threshold is judged as bus voltage software undervoltage fault; input current exceeding the fault threshold is judged as DC forward overcurrent fault; reverse current exceeding the fault threshold is judged as DC reverse overcurrent fault (branch short circuit); and faults caused by abnormal circuit breaker tripping are judged as... The following are considered fault codes: Circuit breaker tripping fault; Inverter module heat sink overheating fault exceeding the fault threshold; Power module reverse current heat sink overheating fault exceeding the fault threshold; During pre-charging, if the voltage of the supporting capacitor 1.7 does not reach the preset value within a predetermined time, it is considered a pre-charging fault; If the voltage exceeds the input reactor overheating fault threshold, it is considered an input reactor winding overheating fault; If the voltage exceeds the output reactor overheating fault threshold, it is considered an output reactor winding overheating fault; If the fuse microswitch 1.8 is open, it is considered an output fuse fault; If there is no light feedback from the fiber optic cable 1.9 and the hardware provides fault information, it is considered a fiber optic feedback fault.

[0057] For Level 6 (Class) faults, the fault alarm handling measure is as follows: when the water supply system's water circuit data reaches the fault threshold, a fault information is sent to the superior authority, requesting a reduction to the minimum speed of the permanent magnet propulsion motor (the rotational speed of the shaft when the permanent magnet propulsion motor rotates). If the superior authority does not respond to the reduction request within the specified time, the speed will be automatically reduced. Level 6 (Class) faults include: when the inlet water temperature exceeds the fault threshold, it is judged as an inlet water overheating fault (Level 2); when the inlet water pressure difference is less than the fault threshold, it is judged as an inlet / outlet water pressure difference fault (Level 2).

[0058] For level 7 (class) faults, the fault alarm handling measure is for the unit to request a reduction in speed from the overall system. If there is no response within the specified time, the speed will be automatically reduced, and the unit will be restored after the alarm disappears. The seven levels (classes) of faults include: Inlet water temperature exceeding the alarm threshold is considered an inlet water over-temperature alarm; inlet water pressure difference exceeding the alarm threshold is considered an inlet water pressure difference alarm; stator winding temperature exceeding the alarm threshold is considered a winding over-temperature alarm; bearing bush temperature exceeding the alarm threshold is considered a bearing bush over-temperature alarm; bus voltage exceeding the alarm threshold is considered a DC bus over-voltage alarm; bus voltage less than the alarm threshold is considered a DC bus under-voltage alarm; inverter module heat sink plate temperature exceeding the alarm threshold is considered an inverter module heat sink plate over-temperature alarm; power module reverse current heat sink plate temperature exceeding the alarm threshold is considered a power module reverse current heat sink plate over-temperature alarm; input reactor winding temperature exceeding the alarm threshold is considered an input reactor winding over-temperature alarm; output reactor winding temperature exceeding the alarm threshold is considered an output reactor winding over-temperature alarm; water accumulation alarm IO signal is read as a water accumulation alarm; inlet water pressure exceeding the alarm threshold is considered an inlet water pressure alarm.

[0059] For Class 8 faults, the fault alarm handling measure is to maintain the unit in the state before the alarm. Class 8 faults include: exceeding the air over-temperature alarm threshold of the frequency converter control equipment is considered an over-temperature alarm; a 10-second interruption of internal CAN1 communication is considered an internal CAN1 communication alarm; a 10-second interruption of internal CAN2 communication is considered an internal CAN2 communication alarm; a 10-second interruption of Ethernet communication is considered an internal Ethernet communication alarm; a 10-second external CAN communication alarm is considered an external CAN communication alarm; and a 10-second interruption of external Ethernet communication is considered an external Ethernet communication fault.

[0060] Based on the above analysis of the hazards and correlations of faults, fault alarms are classified into categories according to their hazards, and their handling methods are summarized.

[0061] S4, in conjunction with the unit's operating logic, formulates corresponding fault alarm handling logic, implements it through code, and finally completes the design of relevant fault protection and control strategies.

[0062] Before performing fault alarm interface correlation analysis and reclassification, the conventional fault alarm handling methods have four levels: fault shutdown, fault standby, branch isolation, and alarm operation. The unit's operation flowchart is as follows: Figure 7 As shown. Compared with conventional fault alarm handling, the fault handling method of this invention changes the complexity through autonomous fault alarm diagnosis and handling design. The fault handling logic is more complex. The original four-level faults are changed to eight levels. Therefore, it is necessary to first consider the design of the priority in order to better design the program.

[0063] This invention addresses the first four levels of faults involved in the shutdown and standby processes. Therefore, the handling of these four types of faults should be parallel, meaning that a higher-level fault should not trigger a lower-level fault response, and both types of faults should respond to the higher-level fault simultaneously. However, the third and fourth types of faults have their own special characteristics. The fault priorities mentioned above do not include the third type of fault during the delay period or the fourth type of fault after reset and restart. In these two stages, other types of fault alarms will also be responded to. The priority relationship table is as follows: different priorities are set for the fault alarm handling methods from low to high: Level I: Fault delay shutdown and after successful automatic restart; Level II: Alarm operation; Level III: Dermination to minimum speed; Level IV: Dermination; Level V: Branch isolation; Level VI: Fault automatic restart shutdown and reset; Level VII: Fault delay shutdown after delay completion; Level VIII: Fault standby; Level IX: Fault shutdown.

[0064] Priorities are arranged from low to high. Based on these priorities, a flowchart for the unit's autonomous fault alarm diagnosis and handling method can be designed, such as... Figure 8 As shown in the diagram, by integrating this autonomous fault alarm and handling mode into the control system according to the corresponding flowchart, autonomous propulsion control and efficient fault alarm diagnosis and handling of the unmanned surface vessel can be achieved.

[0065] The above embodiments are merely illustrative of the principles and effects of the present invention, as well as some of the application examples. For those skilled in the art, various modifications and improvements can be made without departing from the inventive concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A fault diagnosis method for an integrated intelligent variable frequency permanent magnet drive device for unmanned surface vessels, based on an intelligent variable frequency permanent magnet drive device comprising a permanent magnet propulsion motor (2) and an intelligent frequency converter (1) connected above the permanent magnet propulsion motor (2), as well as a control cabinet, an external water supply system, and an oil supply system, characterized in that: The permanent magnet propulsion motor (2) includes a stator (2.1), a rotor (2.2), an end cover (2.3), and a concave end cover bearing (2.4); the intelligent frequency converter (1) includes a controller (1.2), a water-air heat exchanger (1.3), a supporting capacitor (1.7), a fuse micro switch (1.8), and a power module (1.5) located in the AC inverter output area, with an optical fiber (1.9) leading out from below the power module (1.5). It also includes a cooling-control-inlet area (1.1) parallel to the controller (1.2), a DC filter area (1.4) located below the water-air heat exchanger (1.3), and an outlet area (1.6) located below the power module (1.5); including the following steps: S1, classify and summarize the fault information and alarm information that may occur in the propulsion motor system according to the equipment location. The fault information of the intelligent frequency converter (1) is divided into output phase current hardware overcurrent fault, output phase current software overcurrent fault, bus voltage software overvoltage fault, bus voltage hardware overvoltage fault, bus voltage software undervoltage fault, output reactor winding overtemperature fault, input reactor winding overtemperature fault, inverter module heat dissipation base plate overtemperature fault, power module reverse current heat dissipation base plate overtemperature fault, fiber optic feedback fault, pre-charge fault, output fuse fault and control unit power failure fault; the alarm information of the intelligent frequency converter (1) is divided into output reactor winding overtemperature alarm, input reactor winding overtemperature alarm, DC bus overvoltage alarm, DC bus undervoltage alarm, inverter module heat dissipation base plate overtemperature alarm, power module reverse current heat dissipation base plate overtemperature alarm and intelligent frequency converter (1) air temperature too high alarm; The fault information of the permanent magnet propulsion motor (2) is divided into stator winding over-temperature fault, stator winding end over-temperature fault, bearing over-temperature fault and bearing bush over-temperature fault; the alarm information of the permanent magnet propulsion motor (2) is divided into stator winding over-temperature alarm, stator winding end over-temperature alarm, bearing over-temperature alarm, bearing bush over-temperature alarm and water accumulation alarm. The fault information of the control cabinet is divided into DC forward overcurrent fault, DC reverse overcurrent fault, circuit breaker tripping fault, external emergency stop fault, external CAN communication fault and internal CAN communication fault; the alarm information of the control cabinet is divided into internal CAN communication alarm, internal Ethernet communication alarm, external CAN communication alarm and external Ethernet communication alarm. The fault information of the water supply system is divided into inlet water over-temperature fault, inlet and outlet water pressure difference over-pressure fault, and inlet water pressure fault; the alarm information of the water supply system is divided into inlet water over-temperature alarm, inlet water pressure difference alarm, and inlet water pressure alarm. The fault information of the oil supply system is divided into four categories: high lubricating oil temperature, high lubricating oil pressure differential, high lubricating oil pressure, and low lubricating oil pressure. S2 analyzes fault information that may cause serious damage to the permanent magnet drive device, and analyzes the correlation between fault information and alarm information to prevent false triggering. S3 classifies all fault and alarm information according to their severity from high to low and formulates fault handling methods appropriate to each fault level: The first-level fault handling method is to put the whole machine into the fault state and disconnect the circuit breaker; if the fault disappears, the machine will enter the shutdown state after resetting. The secondary fault handling method is to switch the permanent magnet drive unit to standby mode and wait for communication to be restored. The fault information will be automatically cleared. The third-level fault handling method is to report the fault information to the navigation control system and request a shutdown to check the water supply system; The fourth-level fault handling method is to switch the permanent magnet drive unit to the fault state, and automatically restart after a delay. If the fault is not reset, switch to the fault state again and disconnect the power supply. If the fault is reset, it will operate normally. The level 5 fault handling method is to shut down the branch where the fault occurred, while the branch where the fault did not occur continues to operate; The level 6 fault handling method is to send fault information to the superior when the water supply system reaches the fault threshold and request to reduce the speed to the minimum speed of the permanent magnet propulsion motor. If the superior does not respond to the reduction request within the specified time, the speed will be automatically reduced. The level 7 fault handling method is that the permanent magnet drive unit requests the overall speed to be reduced. If there is no response within the specified time, the speed will be automatically reduced and restored after the alarm disappears. The level eight fault handling method is to keep the permanent magnet drive device running in the state before the alarm; S4, combined with the operating logic of the permanent magnet drive device, formulates corresponding fault alarm handling logic.

2. The fault diagnosis method of the integrated intelligent variable frequency permanent magnet driving device of the unmanned vehicle according to claim 1, characterized in that, The first-level fault in step S3 includes: When the inlet water temperature exceeds the fault threshold and the inverter module heat sink plate temperature exceeds the alarm threshold, it is judged as an inlet water over-temperature fault. When the inlet water pressure difference exceeds the fault threshold and the temperature of the inverter module heat sink exceeds the alarm threshold, it is judged as a fault of the inlet and outlet water pressure difference level 1. When the lubricating oil temperature is higher than the fault threshold and the bearing bush temperature is also higher than the fault threshold, it is judged as a fault of lubricating oil temperature being too high. When the temperature of the bearing bush exceeds the fault threshold, it is judged as an over-temperature fault of the bearing bush. When a control unit malfunctions, it is determined to be a control unit malfunction. When an emergency stop command is received, it is determined to be an emergency stop fault.

3. The fault diagnosis method for an integrated intelligent variable frequency permanent magnet drive device for unmanned surface vessels according to claim 2, characterized in that, The secondary faults in step S3 include: When all external CAN communications are interrupted, it is determined that there is an external CAN communication failure. If all internal CAN communication alarms are triggered, it is determined to be an internal CAN communication failure.

4. The fault diagnosis method for an integrated intelligent variable frequency permanent magnet drive device for unmanned surface vessels according to claim 3, characterized in that, The level 3 faults in step S3 include: An inlet water pressure failure is identified when the inlet water pressure exceeds the fault threshold. When the oil pressure differential exceeds the fault threshold, it is judged as a lubricating oil pressure differential fault. When the high oil pressure exceeds the fault threshold, it is judged as a high oil pressure fault. When the oil pressure is lower than the fault threshold, it is judged as a low oil pressure fault.

5. The fault diagnosis method of the integrated intelligent variable frequency permanent magnet driving device of the unmanned vehicle according to claim 4, characterized in that, The level four faults in step S3 include: When the phase current amplitude of a certain phase in both branches of the permanent magnet propulsion motor (2) is greater than the fault threshold, it is judged as a software overcurrent fault in the phase current of the two branches. When the voltage of a certain phase bus is less than the fault threshold in both branches of the permanent magnet propulsion motor (2), it is judged as a software undervoltage fault of the bus voltage of both branches.

6. The fault diagnosis method of the integrated intelligent variable frequency permanent magnet driving device of the unmanned vehicle according to claim 5, characterized in that, The five-level faults in step S3 include: When the stator winding temperature exceeds the fault threshold, it is judged as a winding over-temperature fault. When the bus voltage exceeds the fault threshold, it is judged as a bus voltage software / hardware overvoltage fault. A phase current amplitude greater than the fault threshold is judged as a phase current hardware overcurrent fault. When the amplitude of the phase current in a certain branch exceeds the fault threshold, it is judged as a phase current software overcurrent fault. When the voltage of a certain branch bus is less than the fault threshold, it is judged as a software undervoltage fault of the bus voltage. When the input current exceeds the fault threshold, it is judged as a DC forward overcurrent fault; A DC reverse overcurrent fault is identified when the reverse current exceeds the fault threshold. When a circuit breaker trips abnormally, it is determined to be a circuit breaker tripping fault. An inverter module heat sink base plate overheating fault is identified when the temperature exceeds the fault threshold. When the over-temperature fault of the power module's reverse flow heat dissipation base plate exceeds the fault threshold, it is judged as an over-temperature fault of the power module's reverse flow heat dissipation base plate. During pre-charging, if the voltage of the supporting capacitor (1.7) does not reach the preset value within a predetermined time, it is judged as a pre-charging fault; If the temperature exceeds the input reactor over-temperature fault threshold, it is judged as an input reactor winding over-temperature fault; If the temperature exceeds the over-temperature fault threshold of the output reactor, it is judged as an over-temperature fault of the output reactor winding. When the fuse micro switch (1.8) is open, it is determined that the output fuse is faulty; When there is no light feedback from the fiber optic cable (1.9), the hardware identifies the fault as a fiber optic feedback failure.

7. The fault diagnosis method for an integrated intelligent variable frequency permanent magnet drive device for unmanned surface vessels according to claim 6, characterized in that, The six-level faults in step S3 include: When the inlet water temperature exceeds the fault threshold, it is judged as an inlet water over-temperature level two fault. When the inlet water pressure difference is less than the fault threshold, it is judged as a second-level fault of inlet and outlet water pressure difference.

8. The fault diagnosis method of the integrated intelligent variable frequency permanent magnet driving device of the unmanned vehicle according to claim 7, characterized in that, The seven-level faults in step S3 include: When the inlet water temperature exceeds the alarm threshold, it is determined to be an inlet water over-temperature alarm. An inlet water pressure differential alarm is triggered when the inlet water pressure differential exceeds the alarm threshold. When the stator winding temperature exceeds the alarm threshold, it is determined to be an over-temperature alarm. When the temperature of the bearing bush exceeds the alarm threshold, it is determined to be an over-temperature alarm for the bearing bush. When the bus voltage exceeds the alarm threshold, it is determined to be a DC bus overvoltage alarm. When the bus voltage is less than the alarm threshold, it is judged as a DC bus undervoltage alarm; When the temperature of the inverter module's heat sink plate exceeds the alarm threshold, it is determined to be an over-temperature alarm for the inverter module's heat sink plate. When the temperature of the power module's reverse flow heat dissipation base plate exceeds the alarm threshold, it is determined to be an over-temperature alarm for the power module's reverse flow heat dissipation base plate. When the temperature of the input reactor winding exceeds the alarm threshold, it is determined to be an over-temperature alarm of the input reactor winding. When the temperature of the output reactor winding exceeds the alarm threshold, it is determined to be an over-temperature alarm for the output reactor winding. When a water accumulation alarm IO signal is read, it is determined to be a water accumulation alarm. An inlet water pressure alarm is triggered when the inlet water pressure exceeds the alarm threshold.

9. The fault diagnosis method of the integrated intelligent variable frequency permanent magnet driving device of the unmanned vehicle according to claim 8, characterized in that, The eight-level faults in step S3 include: When the air temperature exceeds the intelligent frequency converter's (1) air over-temperature alarm threshold, it is judged as an air over-temperature alarm; An internal CAN communication interruption is identified as an internal CAN communication alarm. An Ethernet communication interruption is identified as an internal Ethernet communication alarm. When an external CAN communication alarm occurs, it is determined to be an external CAN communication alarm. When external Ethernet communication is interrupted, it is determined to be an external Ethernet communication failure.

10. The fault diagnosis method of the integrated intelligent variable frequency permanent magnet driving device of the unmanned vehicle according to any one of claims 1 to 9, characterized in that, Different priorities are set for fault alarm handling methods: Level I is fault delayed shutdown and after successful automatic restart; Level II is alarm operation; Level III is derated to the minimum speed; Level IV is derated; Level V is branch isolation; Level VI is fault automatic restart shutdown and reset; Level VII is fault delayed shutdown after the delay is completed; Level VIII is fault standby; Level IX is fault shutdown.

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