A shipboard crane anti-interference device and a shipboard crane device

Abstract

The embodiment of the application discloses a marine crane anti-interference device and a marine crane device. The device comprises: a plurality of rectification branches connected in parallel, each rectification branch comprising a rectification transformer, an anti-interference unit and a rectification unit, the anti-interference unit being connected between the rectification transformer and the rectification unit; an inverter unit, the input end of the inverter unit being connected with the output end of the rectification unit of the plurality of rectification branches; and an output reactance unit connected with the output end of the inverter unit. Through the scheme, the source control strategy is adopted to optimize the power signal filtering anti-interference, the output reactance unit is combined to suppress high-frequency peak interference, the influence of harmonics and electromagnetic interference is effectively reduced, and the stable operation of the marine crane in a complex marine electromagnetic environment is ensured.

Description

Technical Field

[0001] This application relates to the field of shipbuilding and marine engineering equipment, and in particular to an anti-interference device for a marine crane and a marine crane device. Background Technology

[0002] During the operation of marine cranes (or floating cranes) at sea, they face multiple interferences from both the marine environment and the ship's systems. Their anti-interference capability directly determines the safety and efficiency of operation in complex marine environments and complex electromagnetic environments of ships.

[0003] However, the current anti-interference design of marine cranes is difficult to adapt to the extreme conditions in the marine environment, resulting in a decrease in the stability and operational accuracy of marine cranes. Summary of the Invention

[0004] This application addresses the aforementioned deficiencies by providing an anti-interference device and a marine crane assembly for marine cranes. This solution, employing multiple parallel rectifier branches in conjunction with an anti-interference unit and an output reactor unit, effectively reduces harmonic interference at its source and suppresses high-frequency spikes generated during motor start-up, shutdown, and load changes, preventing transient interference from being introduced into the control module. Consequently, it significantly improves the operational stability and precision of marine cranes in complex marine environments and the complex electromagnetic environment of ships.

[0005] In a first aspect, an anti-interference device for a marine crane is provided. The device includes: multiple rectifier branches connected in parallel, each rectifier branch including a rectifier transformer, an anti-interference unit, and a rectifier unit, wherein the anti-interference unit is connected between the rectifier transformer and the rectifier unit and is used to filter and suppress interference on the power signal output by the rectifier transformer; an inverter unit, the input terminal of which is connected to the output terminal of the rectifier unit of the multiple rectifier branches; and an output reactor unit connected to the output terminal of the inverter unit and used to suppress interference on the power signal output by the inverter unit.

[0006] This scheme enables multi-pulse rectification (such as 24-pulse rectification) through multiple parallel rectifier branches in conjunction with an anti-interference unit, effectively reducing harmonic content and minimizing conducted interference to the control system. Furthermore, the output reactor unit suppresses high-frequency spikes generated on the inverter unit output side due to motor start-up / stop and load abrupt changes, preventing transient interference from being reverse-coupled to the control module and ensuring stable operation of the crane's power system in harsh sea conditions and complex electromagnetic environments.

[0007] In conjunction with the first aspect, in a possible implementation of the first aspect, the anti-interference unit includes: an AC input reactor, the input terminal of which is connected to the output terminal of the rectifier transformer, for suppressing harmonic currents in the power supply signal output by the rectifier transformer; and a first filter, the input terminal of which is connected to the output terminal of the AC input reactor, and the output terminal of which is connected to the input terminal of the rectifier unit, for filtering out electromagnetic interference.

[0008] This scheme enables the AC input reactor to limit harmonic currents and transient overcurrents, and reduce voltage spikes generated during the switching process of the rectifier unit; the first filter can further filter out high-frequency electromagnetic interference, and the two cascaded together form a dual anti-interference barrier from the power source to the rectifier stage.

[0009] In conjunction with the first aspect, in a possible implementation of the first aspect, the device further includes: a control module, which is communicatively connected to the rectifier branch, the inverter unit, and the output reactor unit respectively; and an isolation transmitter, the input terminal of which is used to receive the analog signal output by the sensor, and the output terminal of which is connected to the input terminal of the control module.

[0010] This solution enables the isolation transmitter to electrically isolate the analog signals (such as 4-20mA differential signals) acquired by the sensor, thereby cutting off the grounding loops and common-mode interference paths caused by long-distance transmission, avoiding signal offset or distortion, ensuring that the sensor data obtained by the control module is accurate and reliable, and improving the closed-loop control accuracy.

[0011] In conjunction with the first aspect, in a possible implementation of the first aspect, the device further includes: a high-frequency bypass capacitor connected in parallel with the sensor.

[0012] This scheme allows high-frequency bypass capacitors (such as 10-100nF) to provide a low-impedance bypass channel for high-frequency interference bands, effectively filtering out high-frequency spikes superimposed on analog signals and preventing high-frequency noise from entering the sampling port of the control module.

[0013] In conjunction with the first aspect, in a possible implementation of the first aspect, the device further includes: a common-mode choke; a differential filter circuit; wherein the common-mode choke and the differential filter circuit are connected in series between the sensor and the input terminal of the control module.

[0014] This scheme uses a common-mode choke (e.g., 1mH) to suppress high-frequency common-mode interference, while a differential filter circuit attenuates low-frequency interference below 50Hz. The two are connected in series to form a wideband anti-interference link, ensuring the integrity of the sensor signal throughout the transmission process.

[0015] In conjunction with the first aspect, in a possible implementation of the first aspect, the device further includes: a control module, which is communicatively connected to the rectifier branch, the inverter unit, and the output reactor unit; and a second filter, the input of which is used to receive digital signals, and the output of which is connected to the input of the control module.

[0016] This scheme enables the second filter (such as an RC filter) to suppress high-frequency spike interference, thereby preventing spike pulses from falsely triggering control actions and significantly improving the anti-interference capability of switching signals and the reliability of system logic.

[0017] In conjunction with the first aspect, in a possible implementation of the first aspect, the device further includes: an isolation transformer connected in series between the control module and the drive module, wherein the control module is communicatively connected to the rectifier branch, the inverter unit and the output reactor unit respectively; and a surge absorber connected to the input terminal of the isolation transformer.

[0018] This solution achieves electrical isolation between the control module and the motor drive cabinet using an isolation transformer, cutting off ground loop conducted interference. The surge absorber absorbs lightning-induced overvoltages and external surge voltages, preventing spikes from entering the control terminal and thus protecting core control components from transient overvoltage damage.

[0019] In conjunction with the first aspect, in a possible implementation of the first aspect, the device further includes: a first control unit; a second control unit; wherein the first control unit and the second control unit are connected in parallel, the first control unit is used to execute control commands, and in the event of an abnormality in the first control unit, the second control unit is used to execute the control commands.

[0020] This solution employs a dual-control unit redundancy architecture. When the main control unit experiences logical anomalies due to interference or faults, the backup control unit can seamlessly take over the critical control logic, preventing single-point failures from causing the crane to lose control and ensuring that safety control commands can still be executed reliably in high-frequency interference environments.

[0021] In conjunction with the first aspect, in a possible implementation of the first aspect, the device further includes: a main bus connected to the first control unit and the second control unit; and a backup bus connected to the first control unit and the second control unit; wherein the main bus and the backup bus are connected in parallel, and in the event of an anomaly in the main bus, the first control unit or the second control unit transmits signals through the backup bus.

[0022] This scheme implements a dual-bus backup mechanism. When the main bus malfunctions, the control unit can automatically switch to the backup bus within one communication cycle to ensure uninterrupted data transmission, thereby guaranteeing the integrity and correctness of the communication data.

[0023] In a second aspect, a marine crane device is provided, including a marine crane anti-interference device as described in any one of the first aspects. Attached Figure Description

[0024] Figure 1 A schematic diagram of the main power supply system and its driver for the anti-interference device for marine cranes provided in an embodiment of this application is shown.

[0025] Figure 2 A schematic diagram illustrating signal interference immunity provided in an embodiment of this application is shown;

[0026] Figure 3 This illustration shows a single-point grounding diagram provided in an embodiment of this application;

[0027] Figure 4 A schematic diagram of fieldbus redundancy provided in an embodiment of this application is shown. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] First, the prior art and technical problems involved in the embodiments of this application are introduced.

[0030] As mentioned earlier, the current anti-interference design of marine cranes is difficult to adapt to the extreme conditions in the marine environment, resulting in a decrease in the stability and operational accuracy of marine cranes.

[0031] For example, the mechanical structure of marine cranes has limitations in its ability to withstand interference. For instance, in complex sea conditions, such as high winds, strong waves, and strong currents, marine cranes experience more complex and severe disturbances. Existing mechanical structure anti-interference designs may struggle to fully adapt to these extreme conditions, leading to a decrease in the stability and operational accuracy of the marine crane.

[0032] As another example, marine cranes lack communication stability in extreme electromagnetic environments. For instance, in extreme electromagnetic environments, such as strong electromagnetic pulse interference or high-frequency interference, the stability and reliability of existing wireless communication systems may be severely affected. This could lead to communication interruptions or data transmission errors between the marine crane and the control center, impacting operational safety and efficiency.

[0033] For another example, large marine cranes are equipped with numerous electronic devices and systems, such as power control systems, communication systems, and navigation systems. These devices and systems may have complex electromagnetic coupling relationships, leading to the propagation and amplification of electromagnetic interference. Existing electromagnetic compatibility designs may struggle to fully account for the coupling effects of these multi-source electromagnetic interferences, thus affecting the stability and reliability of the electronic systems.

[0034] As another example, the ability to cope with nonlinear loads and dynamic changes is limited. For instance, marine cranes may face nonlinear loads and dynamic changes during operation, such as sudden changes in the load or random disturbances from wind and waves. Existing power system anti-interference technologies may struggle to respond to these changes in real time and accurately, leading to unstable power performance of marine cranes.

[0035] Furthermore, the electrical control system of marine cranes mainly includes a central processing unit (CPU) module of a programmable logic controller (PLC), input / output modules, electrical control cabinets, operating consoles, sensor acquisition units, frequency converters, and motors. High-frequency electromagnetic interference (EMI) primarily originates from the starting of high-power motors, frequency converter switching, and ship communication equipment. Lightning strikes and lightning-induced interference create common-mode interference on board, while mechanical interference from conductor vibration and corrosive currents in the seawater environment also introduce low-frequency interference. The ship's steel structure generates 30–50 mV of common-mode noise during the operation of high-power equipment, affecting the communication bus and PLC acquisition terminals. Sensor signal lines and driver control terminals may be subject to high-frequency spike interference, clearly identifying the vulnerable points of the marine crane's electrical control system.

[0036] To address the aforementioned problems, this application provides an anti-interference device for marine cranes. This anti-interference device can be applied to marine cranes. Specifically, this application focuses on the marine crane's own control system, implementing anti-interference measures from four perspectives: source control, transmission suppression, end-point protection, and system redundancy, ensuring the systematic and feasible anti-interference performance of the entire system.

[0037] First, source control focuses on addressing the source of interference by optimizing the motor starting method and using frequency converters and reactors to reduce the generation of high-frequency transient pulses. Figure 1 A schematic diagram of the main power supply system and its driver for the anti-interference device for marine cranes provided in this application embodiment is shown.

[0038] like Figure 1As shown, the anti-interference device for the marine crane includes multiple rectifier branches connected in parallel. Each rectifier branch includes a rectifier transformer, an anti-interference unit, and a rectifier unit. Figure 1 As shown, the anti-interference unit is connected between the rectifier transformer and the rectifier unit, and is used to filter and suppress interference on the power signal output by the rectifier transformer. Furthermore, multiple parallel rectifier branches, in conjunction with the anti-interference unit, can achieve multi-pulse rectification (such as 24-pulse rectification), effectively reducing harmonic content and minimizing conducted interference to the control system itself.

[0039] For example, in an embodiment of this application, two rectifier transformers can be arranged on the main power supply side of the marine crane device, and these two rectifier transformers can form a 24-pulse rectification. Furthermore, as... Figure 1 As shown, the anti-interference unit may include an AC input reactor and a first filter (such as an electromagnetic compatibility filter, EMC filter). The input terminal of the AC input reactor is connected to the output terminal of the rectifier transformer to suppress harmonic currents in the power signal output by the rectifier transformer. The input terminal of the first filter is connected to the output terminal of the AC input reactor, and the output terminal of the first filter is connected to the input terminal of the rectifier unit to filter out electromagnetic interference. Through this scheme, the AC input reactor can limit harmonic currents and transient overcurrents, mitigating voltage spikes generated during the switching process of the rectifier unit. The first filter can further filter out high-frequency electromagnetic interference; the two cascaded together form a dual anti-interference barrier from the power source to the rectification stage.

[0040] In addition, continue to refer to Figure 1 The anti-interference device for the marine crane also includes an inverter unit and an output reactor unit. The input terminal of the inverter unit is connected to the output terminal of the rectifier unit in the multiple rectifier branches, and the output reactor unit is connected to the output terminal of the inverter unit to suppress interference on the power signal output by the inverter unit. Through this scheme, the output reactor unit can suppress high-frequency spikes generated on the output side of the inverter unit due to motor start-up and shutdown and sudden load changes, preventing transient interference from being reverse-coupled to the control module, and ensuring the stable operation of the marine crane's power system in harsh sea conditions and complex electromagnetic environments.

[0041] For example, in an embodiment of this application, the marine crane system can be powered by an isolated uninterruptible power supply (UPS), with the output voltage stable within ±1%, and the capacity configured to be 1.2 times the system's rated power. Furthermore, as... Figure 1As shown, two rectifier transformers can be installed on the main power supply side to form a 24-pulse rectification. Simultaneously, an AC input reactor and an EMC filter are installed at the front end of the rectifier unit to effectively reduce harmonics. At the same time, adding an output reactor at the high-power motor drive effectively suppresses high-frequency spikes generated by motor start-up and stop and load changes, preventing transient interference to the control module. Power line wiring must be strictly separated from signal lines, with perpendicular crossings or a spacing of ≥30cm to reduce coupling interference.

[0042] Subsequently, transmission suppression focuses on using shielded twisted-pair cables, inductor-capacitor (LC) filters, and isolation transformers on signal and power lines to block interference from propagating during transmission. Figure 2 A schematic diagram illustrating signal interference immunity provided in an embodiment of this application is shown. Wherein, as... Figure 2 As shown, connecting analog signals to an isolation transmitter ensures that signals transmitted over long distances do not deviate, while connecting digital signals to a second filter suppresses high-frequency spike interference.

[0043] Specifically, such as Figure 2 As shown, the anti-interference device for the marine crane also includes a control module and an isolation transmitter. The control module is communicatively connected to the rectifier branch, the inverter unit, and the output reactor unit. The input terminal of the isolation transmitter receives the analog signal output from the sensor, and its output terminal is connected to the input terminal of the control module. Through this scheme, the isolation transmitter can electrically isolate the analog signal (such as a 4-20mA differential signal) acquired by the sensor, thereby cutting off grounding loops and common-mode interference paths caused by long-distance transmission, avoiding signal offset or distortion, ensuring the accuracy and reliability of the sensor data obtained by the control module, and improving the closed-loop control accuracy.

[0044] Optionally, in embodiments of this application, the anti-interference device for the marine crane further includes a high-frequency bypass capacitor. This high-frequency bypass capacitor is connected in parallel with the sensor. Through this scheme, the high-frequency bypass capacitor (e.g., 10-100nF) can provide a low-impedance bypass channel for the high-frequency interference band, effectively filtering out high-frequency spikes superimposed on the analog signal and preventing high-frequency noise from entering the sampling port of the control module.

[0045] Optionally, in embodiments of this application, the anti-interference device for the marine crane further includes a common-mode choke and a differential filter circuit. The common-mode choke and the differential filter circuit are connected in series between the sensor and the input terminal of the control module. Furthermore, through this scheme, the common-mode choke (e.g., 1mH) can suppress high-frequency common-mode interference, while the differential filter circuit attenuates low-frequency interference below 50Hz. The two are connected in series to form a wideband anti-interference link, ensuring the integrity of the sensor signal throughout the transmission process.

[0046] Continue to refer to Figure 2 The anti-interference device for the marine crane also includes a second filter (such as a resistor-capacitor (RC) filter). The input of this second filter receives digital signals, and its output is connected to the input of the control module. This design allows the second filter to suppress high-frequency spike interference, preventing false triggering of control actions by spike pulses and significantly improving the anti-interference capability of switching signals and the reliability of system logic.

[0047] For example, based on Figure 2 The scheme shown in this application's embodiments, in its signal-level anti-interference design, ensures that sensor signals, PLC input / output, and encoder signals remain stable and reliable in complex electromagnetic environments. Analog signals can employ 4-20mA standard differential transmission to effectively suppress common-mode interference. When the transmission distance exceeds 30 m, this application embodiment can add an isolation transmitter between the sensor and PLC ends. The isolation level of this transmitter can be selected as 2500V to ensure that long-distance transmission will not be affected by ground loops or interference voltages, preventing signal deviation. Furthermore, this application embodiment can install an RC filter (i.e., a second filter) at the PLC input terminal corresponding to the digital signal. R is 1 kΩ, and C is 100nF. This can suppress high-frequency spike interference to one-tenth of its original amplitude. In addition, a transient voltage suppressor (TVS) tube can be installed in each digital input line to absorb instantaneous spike voltages within ±24V, protecting the PLC port from damage.

[0048] Furthermore, the encoder signal in this embodiment can be output using A / B differential output, and the wiring design should keep it as far away from high-voltage cables as possible, maintaining a minimum spacing of over 50cm to prevent high-frequency electromagnetic radiation coupling. Additionally, the signal line shielding layer can be grounded at a single point at the PLC terminal to minimize ground loops and prevent common-mode interference from propagating through the grounding loop. Moreover, for high-frequency interference bands (e.g., 50-500kHz), this embodiment can add a high-frequency bypass capacitor (e.g., 10-100nF) at the analog signal terminal; for low-frequency interference (e.g., <50Hz), this embodiment can use a common-mode choke (1mH) combined with a differential filter circuit for suppression.

[0049] Then, end protection can be achieved by installing signal isolators, surge protectors, RC snubber circuits, etc. at the sensor, PLC input terminal and driver terminal to prevent high frequency spikes and surge voltages from damaging the control components.

[0050] Optionally, in embodiments of this application, the anti-interference device for the marine crane further includes an isolation transformer and a surge absorber. The isolation transformer is connected in series between the control module and the drive module, and the surge absorber is connected to the input terminal of the isolation transformer. Through this scheme, the isolation transformer achieves electrical isolation between the control module and the motor drive cabinet, cutting off ground loop conducted interference. The surge absorber can absorb lightning-induced overvoltages and external surge voltages, preventing spikes from entering the control terminal, thereby protecting core control components from transient overvoltage damage.

[0051] Optionally, Figure 3 A schematic diagram of a single-point grounding provided in an embodiment of this application is shown. Wherein, as... Figure 3 As shown, the power supply shielding layer is grounded at a single point on the PLC terminal and at the motor control center (MCC) cabinet to prevent the formation of a closed loop that introduces common-mode interference. For example, in the embodiments of this application, the grounding design can adopt a combination of single-point grounding of the hull and equipotential bonding. Specifically, the cross-sectional area of ​​the PLC control cabinet ground wire is not less than 16mm², and the grounding resistance is ≤1Ω to ensure stable ground potential and reduce the propagation of high-frequency interference along the ground wire. The power supply shielding layer is grounded at a single point on the PLC terminal to prevent the formation of a closed loop that introduces common-mode interference. Furthermore, key control modules and the motor drive cabinet are electrically isolated using an isolation transformer, with the transformer capacity selected to be 1.2 times the rated current. In addition, a surge absorber can be added to the input of the isolation transformer to absorb lightning strikes and external surge voltages, preventing spikes from being transmitted to the control terminal.

[0052] Finally, system redundancy can be achieved through dual PLC redundancy, dual bus backup, and communication heartbeat detection mechanisms to ensure the continuous and reliable operation of critical control logic. Figure 4 A schematic diagram of fieldbus redundancy provided in an embodiment of this application is shown. When a bus malfunctions, the PLC can automatically switch to a backup bus within one communication cycle, ensuring uninterrupted data transmission.

[0053] Specifically, such as Figure 4 As shown, the anti-interference device for the marine crane also includes a first control unit and a second control unit. The first and second control units are connected in parallel. The first control unit executes control commands, and in the event of an anomaly in the first control unit, the second control unit executes the control commands. This scheme employs a dual-control unit redundancy architecture. When the main control unit experiences a logic anomaly due to interference or failure, the backup control unit can seamlessly take over the critical control logic, preventing single-point failures from causing crane loss of control and ensuring that safety control commands can continue to be reliably executed even in high-frequency interference environments.

[0054] And continue to refer to Figure 4The anti-interference device for the marine crane also includes a main bus and a backup bus. The main bus is connected to both the first and second control units. The backup bus is also connected to both control units. The main bus and backup bus are connected in parallel. In the event of a failure on the main bus, either the first or second control unit transmits signals via the backup bus. This scheme achieves a dual-bus backup mechanism. When the main bus fails, the control unit can automatically switch to the backup bus within one communication cycle, ensuring uninterrupted data transmission and thus guaranteeing the integrity and correctness of the communication data.

[0055] For example, in the embodiments of this application, the PLC program can adopt a modular design. Considering system stability, the entire system employs a redundant CPU and redundant bus design. The input signal sampling period is 10 milliseconds, with added debouncing and filtering logic. Transient pulses exceeding ±5% of the range are automatically ignored and resampled after a delay. Critical control section logic has the highest priority, ensuring stable execution of safety control commands even in high-frequency interference and transient spike environments. Furthermore, the communication bus uses industrial shielded twisted-pair cable, maintaining a ≥30cm gap between the wiring and high-voltage power lines, with common-mode chokes (1mH) added at both ends to suppress high-frequency common-mode interference. The communication cycle is set to 2ms, supporting dual-network redundancy and a heartbeat detection mechanism. In the event of a main bus malfunction, the PLC can automatically switch to the backup bus within one communication cycle, ensuring continuous and uninterrupted data transmission. In addition, the PLC internal program adds CRC check, data retransmission and anomaly detection mechanisms to ensure the integrity and correctness of communication data. Analog signal sampling uses moving average filtering, upper and lower limit judgment and short-term peak ignoring logic, and digital signals use edge removal jitter of 5-10 milliseconds to prevent spike pulses from erroneously triggering control actions.

[0056] The anti-interference device for marine cranes proposed in this application can be applied to marine crane devices. In other words, a marine crane device may include the anti-interference device for marine cranes described above.

[0057] It should be noted that in the examples and description of this patent, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0058] Although this application has been illustrated and described with reference to certain preferred embodiments thereof, those skilled in the art should understand that various changes in form and detail may be made thereto without departing from the spirit and scope of this application.

Claims

1. An anti-interference device for a marine crane, characterized in that, include: Multiple rectifier branches are connected in parallel. Each rectifier branch includes a rectifier transformer, an anti-interference unit, and a rectifier unit connected in series. The anti-interference unit is connected between the rectifier transformer and the rectifier unit and is used to filter and suppress interference on the power signal output by the rectifier transformer. An inverter unit, the input terminal of which is connected to the output terminal of the rectifier unit of the multiple rectifier branches respectively, is used to output rectified power signals; An output reactor unit is connected to the output terminal of the inverter unit and is used to suppress interference in the rectified power supply signal.

2. The apparatus according to claim 1, characterized in that, The anti-interference unit includes: An AC input reactor, the input terminal of which is connected to the output terminal of the rectifier transformer, is used to suppress harmonic currents in the power supply signal output by the rectifier transformer; A first filter, the input of which is connected to the output of the AC input reactor, and the output of which is connected to the input of the rectifier unit, is used to filter out electromagnetic interference.

3. The apparatus according to claim 1 or 2, characterized in that, Also includes: The control module is communicatively connected to the rectifier branch, the inverter unit, and the output reactor unit, respectively. An isolation transmitter is provided, the input of which is used to receive analog signals output by a sensor, and the output of which is connected to the input of a control module.

4. The apparatus according to claim 3, characterized in that, Also includes: A high-frequency bypass capacitor is connected in parallel with the sensor.

5. The apparatus according to claim 3, characterized in that, Also includes: Common mode choke; Differential filter circuit; The common-mode choke and the differential filter circuit are connected in series between the sensor and the input terminal of the control module.

6. The apparatus according to claim 1 or 2, characterized in that, Also includes: The control module is communicatively connected to the rectifier branch, the inverter unit, and the output reactor unit, respectively. The second filter has an input terminal for receiving digital signals and an output terminal connected to the input terminal of the control module.

7. The apparatus according to claim 1 or 2, characterized in that, Also includes: An isolation transformer is connected in series between the control module and the drive module. The control module is communicatively connected to the rectifier branch, the inverter unit, and the output reactor unit, respectively. A surge absorber is connected to the input terminal of the isolation transformer.

8. The apparatus according to claim 1 or 2, characterized in that, Also includes: First control unit; Second control unit; The first control unit and the second control unit are connected in parallel and are communicatively connected to the rectifier branch, the inverter unit and the output reactor unit, respectively. The first control unit is used to execute control commands, and the second control unit is used to execute the control commands in the event of an abnormality in the first control unit.

9. The apparatus according to claim 8, characterized in that, Also includes: The main bus is connected to the first control unit and the second control unit; A backup bus is connected to the first control unit and the second control unit; The main bus and the backup bus are connected in parallel. In the event of an abnormality in the main bus, the first control unit or the second control unit transmits signals through the backup bus.

10. A marine crane device, characterized in that, Includes the anti-interference device for marine cranes as described in any one of claims 1 to 9.

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