Modular manufacturing process of new energy ship direct current distribution board

Abstract

The application discloses a kind of modular manufacturing process of new energy ship direct current distribution board, belong to ship electrical equipment manufacturing technical field.The process includes: functional module division and standardization interface design, cabinet frame modular assembly and moisture-proof treatment, parameterized design and processing of busbar, processing and insulation strengthening treatment of laminated insulation board, power module pre-installation and graded aging test, modular integrated assembly and pre-charging loop integration, layered wiring in cabinet, insulation detection and dielectric strength test, system commissioning and function verification, packaging and delivery.The application replaces non-standard customization by modular selection design, replaces manual operation by CNC parameterized busbar processing, improves voltage resistance performance by impregnation insulation treatment, and integrates pre-charging loop in assembly process.The application effectively shortens the manufacturing cycle, improves product consistency and reliability, and is suitable for production and manufacturing of new energy ship direct current distribution board.

Description

Technical Field

[0001] This invention relates to the field of marine electrical equipment manufacturing technology, specifically to a modular manufacturing process for DC power distribution boards for new energy ships, applicable to the production and manufacturing of DC power distribution boards for pure battery-powered ships, hybrid power ships, and photovoltaic / wind-assisted power ships. Background Technology

[0003] Currently, some domestic companies have begun R&D and production of marine DC power distribution boards, with some having developed a full range of products from 5.5kW to 355kW. These products must meet classification society specifications and national industry standards, and most are still custom-made. However, the manufacturing process for existing DC power distribution boards for new energy ships still faces the following technical challenges:

[0004] Firstly, DC switchboards are typically non-standard, customized products. Different ship types have varying requirements for the power rating, number of branches, and protection level of the switchboards. Traditional manufacturing methods employ a "one ship, one design; one board, one production" approach, resulting in high design redundancy, long production cycles, and difficulty in ensuring consistent quality. Although some companies have adopted modular design concepts, a systematic modular manufacturing process has not yet been established. The interfaces between functional units lack unified standards, making it difficult to reuse modules across different projects.

[0005] Secondly, the DC distribution board integrates multiple functional units, including a lithium battery charging and discharging module, a new energy power generation MPPT controller, an inverter, a chopper, and an insulation monitoring device. These units are connected via busbars and cables. In traditional assembly processes, busbar processing and wiring rely heavily on manual operations on-site. Workers need to manually bend and punch copper busbars based on on-site measurements, resulting in low production efficiency, poor processing accuracy, and a high risk of wiring errors, leading to a high rework rate.

[0006] Third, the DC switchboards on new energy ships withstand high DC voltages (typically DC 750V or DC 1000V) and large short-circuit currents during operation. DC short-circuit currents lack a natural zero-crossing point, making interruption difficult and placing higher demands on the current-carrying capacity, insulation spacing, and heat dissipation design of the internal busbars. Although existing marine switchboard frames employ an assembly structure, the insulation treatment process for high DC voltages is still imperfect, and the insulation performance of laminated insulation components deteriorates significantly after machining.

[0007] Fourth, DC distribution boards contain a large number of power electronic modules. The energy storage capacitors in these modules generate inrush currents several times the rated current at the moment of activation. Although there are existing designs for DC bus pre-charging circuits, these designs mainly focus on the circuit design level and have not yet been integrated with the manufacturing process. The lack of installation specifications and functional verification procedures for the pre-charging circuit during the assembly stage leads to insufficient reliability of the pre-charging function in actual products.

[0008] Fifth, marine switchboards are subjected to harsh environments of high temperature, high humidity, and salt spray corrosion for extended periods, requiring extremely stringent insulation treatment. Existing processes are mainly designed for AC switchboards and are insufficiently adapted to the high voltage and high current conditions unique to DC switchboards. In particular, there is a lack of systematic process solutions for restoring the insulation performance of laminated insulation components after machining.

[0009] To address the aforementioned issues, this invention provides a modular manufacturing process for DC power distribution boards in new energy ships. Through standardized module design, parameterized busbar processing, laminated insulation reinforcement treatment, step-by-step integrated assembly with pre-charge detection, and systematic debugging and testing, high-quality and efficient manufacturing of DC power distribution boards is achieved. Summary of the Invention

[0010] The purpose of this invention is to provide a modular manufacturing process for DC power distribution boards for new energy ships, in order to solve the technical problems in the prior art, such as high degree of customization, long production cycle, difficulty in ensuring assembly accuracy and consistency, insufficient insulation treatment, and lack of process guarantee for pre-charge protection, so as to realize the standardized design, parametric processing, modular assembly and systematic testing of DC power distribution boards.

[0011] To achieve the above-mentioned objectives, this invention provides a modular manufacturing process for a DC power distribution board for new energy ships, comprising the following steps:

[0012] Step 1: Based on the configuration requirements of the ship's power system, the DC switchboard is divided into several standard functional modules, including DC bus module, lithium battery charging and discharging access module, new energy power generation access module, propulsion frequency converter output module, daily inverter output module, energy management control module and insulation monitoring module. The standard installation dimensions, electrical interface forms and communication protocols of each module are determined to form a standard module library.

[0013] Step 2: Assemble the cabinet using standardized cabinet frame profiles and partitions to form a main cabinet frame with multiple independent compartments, and install removable moisture-proof components at the bottom of the cabinet.

[0014] Step 3: Based on the voltage level and current carrying capacity requirements of the DC distribution board, calculate and determine the cross-sectional area and insulation spacing of the DC positive and negative busbars, and use a CNC busbar processing machine to perform parametric processing and surface treatment on the copper busbars;

[0015] Step 4: Cut, drill holes, and impregnate the laminated insulating components, and test their insulation performance;

[0016] Step 5: Perform pre-assembly and graded aging tests on the power devices and circuit board assemblies in each functional module;

[0017] Step Six: Assemble the pre-installed and tested functional modules according to the compartment positions determined in Step Two. The DC side of the power module is connected to the DC busbar through a DC switch assembly, and the AC side is equipped with a pre-charge circuit.

[0018] Step 7: Perform layered wiring inside the cabinet, measure the contact resistance at the busbar connection, and complete the wiring verification, continuity and insulation resistance test;

[0019] Step 8: Perform insulation testing and dielectric strength testing;

[0020] Step 9: Connect to the simulation test platform for system integration testing, including pre-charging timing verification, energy management scheduling function verification, and short-circuit protection coordination testing;

[0021] Step 10: Clean, package, and include the factory technical documents with the cabinet.

[0022] Specifically, in step one, the DC bus module adopts a distributed segmented bus structure. The left DC busbar is composed of several DC busbar units, and each pair of adjacent DC busbar units is connected by a DC circuit breaker. The right DC busbar is composed of several DC busbar units, and each pair of adjacent DC busbar units is connected by a DC circuit breaker. The two busbars are connected by a bus tie switch.

[0023] Specifically, in step one, the power levels of each module in the standard module library are configured in a series of 5.5kW~355kW.

[0024] Specifically, in step two, the moisture-proof component includes a removable storage box containing a desiccant. An air inlet is opened at the front of the storage box, and a honeycomb mesh panel is installed on the top. The dried air is discharged through the ventilation and exhaust holes on the top of the cabinet.

[0025] Specifically, in step three, the bending angle error of the copper busbar processing shall not exceed ±1°, and the hole positioning error shall not exceed ±0.5mm; the surface treatment process includes pickling to remove the oxide layer → grinding to remove burrs → coating a conductive protective layer → drying and curing, wherein the conductive protective layer is a tin-plated layer or a silver-plated layer, and the plating thickness is 8~15μm.

[0026] Specifically, in step four, the laminated insulation component uses epoxy glass cloth laminate, and the cutting is done with silicon carbide abrasive wheel and water cooling; the hole processing adopts hot punching process, the board is preheated at 100~120℃, and the punching die gap is 10%~15% of the thickness of the laminate; the impregnation insulation treatment includes: pre-baking at 100±5℃ for 3~4 hours, cooling to 40~50℃ and immersing in epoxy resin insulating varnish, drying for 30~60 minutes, and curing at 100±5℃ for 4~5 hours.

[0027] Specifically, in step five, the graded aging test includes: the first-level aging test is to run continuously for 4 to 8 hours under the conditions of 1.1 times the rated voltage and an ambient temperature of 40 to 50°C; the second-level aging test is a pre-test of the control module's communication function to verify the reliability of data interaction between the CAN, RS485, and Ethernet communication interfaces.

[0028] Specifically, in step six, the pre-charging circuit includes a pre-charging contactor and a pre-charging resistor. The pre-charging contactor is connected in parallel with the main contactor, and the pre-charging resistor is connected in series in the pre-charging contactor branch. When the module is put into operation, the pre-charging contactor is first closed to charge the energy storage capacitor with current limiting. When the capacitor voltage reaches more than 90% of the bus voltage, the main contactor is closed and the pre-charging branch is cut off.

[0029] Specifically, in step seven, the busbar connection is tightened with a torque wrench to the set torque, and the contact resistance is measured with a micro-ohmmeter. If the contact resistance exceeds the set threshold, the surface treatment and tightening operation are repeated. The control signal line and communication cable are kept at a distance of not less than 100mm from the power cable. The signal line is a shielded cable, and the shielding layer is grounded at a single point on the control end.

[0030] Specifically, in step eight, the insulation test includes using a 500V or 1000V megohmmeter to measure the insulation resistance between the positive and negative terminals of the DC busbar and between the positive and negative terminals and ground. The insulation resistance value is not less than 20MΩ. The dielectric strength test involves applying an AC withstand voltage of 1000V plus twice the rated voltage between the DC busbar and ground for 1 minute without any breakdown or flashover.

[0031] The modular manufacturing process of the DC power distribution board for new energy ships of this invention has the following advantages compared with the prior art:

[0032] (1) The invention realizes the transformation of DC power distribution board from “one ship, one design” to “modular selection” through functional module division and standardized interface design. Different ship types can select and combine from the standard module library according to power requirements. The standard module library covers power levels from 5.5kW to 355kW, which greatly shortens the design cycle and improves product consistency and maintainability.

[0033] (2) The present invention adopts a distributed segmented busbar structure. The left busbar and the right busbar are respectively composed of several busbar units connected in series by DC circuit breakers, which can effectively reduce the short-circuit current of the DC power grid and reduce the difficulty of selecting DC switching components and configuration costs. The bus tie switch is open under normal operating conditions to realize zoned power supply. When a single busbar fails, the bus tie switch is automatically closed to ensure the continuity of power supply to critical loads.

[0034] (3) This invention uses a CNC busbar processing machine for parametric busbar processing, replacing traditional manual bending and punching with CNC machining. The bending angle error does not exceed ±1°, and the hole positioning error does not exceed ±0.5mm, effectively improving the busbar processing accuracy and assembly efficiency. Combined with a systematic surface treatment process of pickling → polishing → tin / silver plating → drying, the plating thickness is controlled at 8~15μm, ensuring the conductivity and corrosion resistance of the busbar;

[0035] (4) This invention proposes a special laminated insulation board processing and insulation strengthening process for high-voltage DC distribution boards. Water-cooled cutting with a silicon carbide abrasive wheel avoids thermal damage to the laminated board; hot punching at 100~120℃ avoids delamination during punching; and a four-stage impregnation process of "pre-baking → impregnation → drying → curing" restores and improves the insulation performance after machining, forming a three-level insulation quality assurance system of "component level → module level → complete machine level".

[0036] (5) The present invention integrates the pre-charging circuit installation and testing process in the assembly process. By setting a pre-charging contactor and a pre-charging resistor on the AC side of the power module, the pre-charging function is pre-verified in step five, the pre-charging circuit installation is standardized in step six, and the complete pre-charging timing is debugged in step nine, ensuring that the inrush current of the power module is effectively suppressed from the manufacturing source;

[0037] (6) This invention features a modular moisture-proof component at the bottom of the cabinet, which uses a desiccant to absorb moisture from the incoming air, achieving a synergistic effect of air drying and heat dissipation inside the cabinet. The storage box adopts a pull-out structure, facilitating regular replacement of the desiccant and meeting the requirements of the high-humidity environment on ships. Metal partitions are installed between the compartments to achieve electromagnetic shielding and fault isolation, improving the electromagnetic compatibility and safety of the product. Attached Figure Description

[0038] Figure 1 This is a flowchart illustrating the modular manufacturing process of the DC power distribution board for new energy ships according to the present invention. Detailed Implementation

[0039] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0040] Example 1: Manufacturing of DC power distribution board for a new energy sightseeing ship

[0041] A certain new energy sightseeing vessel is equipped with a 300kWh lithium iron phosphate battery pack as its main power source, a 20kW photovoltaic power generation system and a 10kW wind power generation system as auxiliary power sources, two 50kW propulsion motors, and a 20kW daily load. Based on load requirements, such as... Figure 1 As shown, a DC power distribution board for a new energy ship is manufactured according to the manufacturing process of this invention.

[0042] Execution status of step one:

[0043] Based on the ship's electrical system configuration requirements, the following modules are selected from the standard module library:

[0044] DC bus module: 2000A distributed segmented bus, the left busbar is divided into 2 sections connected by DC circuit breakers, the right busbar is divided into 2 sections connected by DC circuit breakers, and one bus tie switch is installed;

[0045] Lithium battery charging and discharging access module: 2 x 300kW-level modules (corresponding to 2 battery packs);

[0046] Photovoltaic power generation access module: 1 x 30kW module;

[0047] Wind power grid connection module: 1 x 30kW module;

[0048] Propulsion frequency converter output module: 2 modules of 100kW level (corresponding to 2 propulsion motors);

[0049] Daily inverter output module: 1 20kW module;

[0050] Energy management control module: includes PLC controller and communication interface;

[0051] Insulation monitoring module: 1 unit.

[0052] The mechanical interfaces of each module use standardized mounting holes (4-M8 threaded holes, 100mm×100mm hole spacing), and the electrical interfaces use standardized connectors (quick-connect copper busbar connectors on the DC side and terminal blocks on the AC side). The design confirmation period is 1.5 working days.

[0053] Step 2 execution status:

[0054] The cabinet is assembled using standardized cabinet frame profiles, with dimensions of 2200mm (height) × 1600mm (width) × 800mm (depth). The interior is divided into 7 independent compartments by vertical and horizontal partitions.

[0055] Upper compartment (1 unit): Installs energy management control module and insulation monitoring module;

[0056] Central compartment (1 unit): for installing DC bus modules;

[0057] Lower left compartment (3): respectively installed lithium battery charging and discharging access module, photovoltaic power generation access module, and wind power generation access module;

[0058] The lower right compartment (2 units): respectively houses the propulsion inverter output module and the daily use inverter output module.

[0059] The compartments are separated by 2mm thick galvanized steel plates, with reliable grounding. Moisture-proof components are installed at the bottom of the cabinet, and each storage box contains 2kg of silica gel desiccant. The air inlet faces forward, and the honeycomb mesh panel faces upward, forming a convection channel with the ventilation and exhaust vents at the top of the cabinet. The frame assembly cycle is 2 working days.

[0060] Execution status of step three:

[0061] Based on current carrying capacity calculations, TMY type T2 copper busbars with dimensions of 80mm × 8mm (cross-sectional area 640mm²) are selected. CNC busbar machining is employed, with the main processes as follows:

[0062] Copper busbar cutting: The length is cut according to the design drawings, and the error is controlled within ±1mm;

[0063] Punching: The connecting holes are made of Φ13mm round holes, with a positioning error of ≤±0.5mm;

[0064] Bending: 3 right-angle bends, bending angle 90°±0.5°, bending radius R=80mm;

[0065] Deburring: Use a flat file and sandpaper to remove all burrs from punch holes and bends;

[0066] Pickling: Immerse in a 10% dilute sulfuric acid solution for 5 minutes to remove the surface oxide layer;

[0067] Tin plating: The tin plating layer is 10μm thick and evenly covers the surface of the copper busbar;

[0068] Drying and curing: Dry in an oven at 120℃ for 30 minutes.

[0069] After the processed busbars pass inspection, they are categorized and stored in a dry and clean area for later use. The processing cycle for the busbars is 2 working days.

[0070] Step 4 execution status:

[0071] Insulation processing is performed on the busbar support plates (4 pieces), switch mounting plates (6 pieces), and outgoing line plates (2 pieces):

[0072] (1) Material selection: 3240 epoxy glass cloth laminate, with thicknesses of 10mm (support plate) and 6mm (mounting plate).

[0073] (2) Cutting process: A silicon carbide abrasive wheel cutting machine is used for cutting. The abrasive wheel diameter is 400mm, the thickness is 5mm, and the speed is 3000r / min. Water is added for cooling and the exhaust system is turned on during cutting. The cut surface is flat and free from delamination, fuzzing or surface carbonization.

[0074] (3) Hole processing: Hot stamping process is adopted, and the sheet metal is preheated in an oven at 110℃ for 40 minutes. The die clearance is set at 12% of the sheet thickness, and the punching diameter is determined according to the bolt specifications as Φ8.5mm (for M8 bolts) and Φ13mm (for M12 bolts). The distance between the hole and the edge of the sheet metal is ≥3 times the sheet thickness. The punching edge is neat and free from delamination and cracking.

[0075] (4) Insulation impregnation treatment:

[0076] Pre-drying: Place the processed laminate into a constant temperature oven and pre-dry at 100±5℃ for 4 hours;

[0077] Impregnation: H30-2 epoxy resin insulating varnish was used, diluted with xylene to a viscosity of 18 seconds (25℃), and filtered through a 200-mesh copper wire mesh. The pre-baked laminate was cooled to 45℃ and then immersed in the varnish for 15 minutes.

[0078] Air dry: Hang vertically and air dry in a dust-free environment for 45 minutes;

[0079] Curing: Place in an oven and cure at 100±5℃ for 5 hours.

[0080] Inspection: After curing, check that the paint film is uniform and glossy, without bubbles, accumulation, or unpainted areas.

[0081] (5) Insulation performance test: Under standard environment (20±5℃, relative humidity 65%), the insulation resistance between the nearest charged points (15mm spacing) is measured with a 500V high resistance meter and is 520MΩ, which meets the requirement of ≥500MΩ.

[0082] The processing cycle for insulating components is 2.5 working days.

[0083] Step 5 execution status:

[0084] After each power module arrives, it undergoes graded aging tests on a dedicated aging test bench:

[0085] (1) Level 1 Aging Test: Two bidirectional DC / DC converters, two drive inverters, and one household inverter were operated with resistive loads at 1.1 times the rated voltage of 750V DC (i.e., 825V DC). The ambient temperature was 45±2℃, and the test was conducted continuously for 6 hours. During the test, the power module temperature rise was ≤65K, the output voltage fluctuation was ≤±2%, and there were no protection trips or abnormal alarms.

[0086] (2) Second-level aging test: The energy management control module is connected to a simulator to simulate typical ship operating conditions (speed changes, load switching, battery SOC changes, etc.) and test the data interaction reliability of the communication interface. CAN communication bit error rate ≤10⁻ 6 RS485 communication response time ≤50ms, Ethernet communication packet loss rate ≤0.1%.

[0087] (3) Pre-charge function verification: For the module equipped with a pre-charge circuit (pre-charge contactor + 100Ω / 50W pre-charge resistor), the commissioning process was simulated for testing. The pre-charge time constant τ=RC=100Ω×2000μF=0.2s, and the time for the capacitor voltage to reach 90% of the bus voltage (i.e. 675V) was measured to be about 0.46s (about 2.3τ), which is consistent with the theoretical calculation, and the pre-charge function is normal.

[0088] The module pre-installation and aging test cycle is 3 working days.

[0089] Step Six Execution Status:

[0090] Modular integration assembly is carried out according to the assembly process:

[0091] (1) DC busbar installation: Install the tinned copper busbars onto the insulating support in the middle compartment of the cabinet. The distance between the positive and negative busbars should be ≥30mm, and the distance between the busbars and the ground (cabinet frame) should be ≥25mm. The insulating support is made of polycarbonate material with a flame retardant rating of UL94 V-0. The busbar connecting bolts are M12 galvanized bolts. Set the torque wrench to 70 N·m, tighten each bolt individually, and mark them.

[0092] (2) Power module installation: Install each power module in the corresponding compartment. The DC side is connected to the busbar through a quick-connect copper busbar connector, and the AC side is connected to the load cable through a terminal block. The pre-charge circuit of each module is installed according to the drawings. The pre-charge contactor (rated current 20A) is connected in parallel with the main contactor (rated current 400A), and a 100Ω / 50W pre-charge resistor is connected in series in the pre-charge branch.

[0093] (3) Control module installation: The PLC controller is installed in the upper compartment and connected to each power module controller via shielded communication cable (RVSP 2×2×0.75mm²). The shielding layer is grounded at a single point at the PLC end, and the grounding resistance is ≤0.1Ω.

[0094] The integration and assembly cycle is 3.5 working days.

[0095] Execution status of step seven:

[0096] Follow the hierarchical wiring principle for cabinet wiring:

[0097] (1) Power cable: The busbar and the power module are connected by a copper busbar flexible connection (thickness 2mm, width matched according to current carrying capacity). After connection, the contact resistance is measured with a micro ohmmeter. The contact resistance of each connection point is 28~45μΩ, which meets the requirement of ≤50μΩ.

[0098] (2) Signal cables: laid along the cable tray on the left side of the cabinet, with a distance of ≥150mm between the cable tray and the power busbar. Shielded cables (RVVP 2×0.75mm²) are used, and the shielding layer is grounded at a single point at the PLC end.

[0099] (3) Secondary wire bundle fixing: The wire bundle is tied in sections along the cabinet frame with a tying interval of 120mm. The cable ties are made of flame-retardant nylon.

[0100] (4) Wiring verification: Two people check each wire one by one. After confirming that the markings are consistent with the drawings, use a cable tester to perform a continuity test. All wires are connected. Insulation resistance test (500V megohmmeter): The insulation resistance of each circuit to ground is ≥50MΩ.

[0101] The verification period for wiring and connection is 4 working days.

[0102] Execution status of step eight:

[0103] (1) Insulation resistance test: A 1000V megohmmeter was used. The insulation resistance between the positive and negative busbars was 50MΩ, the positive pole to ground was 55MΩ, and the negative pole to ground was 52MΩ. All of them were ≥20MΩ, which met the requirements.

[0104] (2) Dielectric strength test: Apply 2500V AC withstand voltage (2×750+1000=2500V) to ground on the busbar for 1 minute, and there is no breakdown, flashover or abnormal sound.

[0105] (3) Insulation monitoring function verification: The simulated positive electrode is grounded through a 100kΩ resistor. The insulation monitoring module displays a grounding resistance of 98kΩ, alarms and locates the faulty branch (branch 1). The accuracy meets the requirements.

[0106] The insulation testing and withstand voltage testing cycle is 1.5 working days.

[0107] Execution status of step nine:

[0108] Connect to the simulation test platform for system integration testing:

[0109] (1) Pre-charge joint commissioning: Test the timing of each power module's activation one by one. After the pre-charge contactor closes, the capacitor voltage rises to ≥675V within 0.5s. Then the main contactor closes and the pre-charge contactor opens. There is no abnormal inrush current throughout the process.

[0110] (2) Lithium battery connection and debugging: The simulated BMS sends a "discharge allowed" signal, the charging and discharging module starts, and the output is stable at 750VDC. The simulated BMS sends an "overvoltage alarm", and the module stops charging and alarms within 0.5s.

[0111] (3) New energy access and commissioning: Simulated photovoltaic input (0~600V DC), MPPT controller tracking efficiency ≥99%, smooth grid connection / disconnection switching.

[0112] (4) Energy management commissioning: Simulate power supply of a single battery pack → start-up of 50kW propulsion load → commissioning of 20kW daily load. The energy management system automatically adjusts, and the bus voltage fluctuation is ≤±5%. Simulate a fault on the left bus. The bus tie switch automatically closes within 0.3s, and the right bus supplies power to the critical load on the left.

[0113] (5) Short circuit protection coordination test: Simulate a short circuit in the propulsion branch (current 2500A). The circuit breaker of the branch trips within 0.02s, the bus voltage recovery time is ≤0.1s, and other branches are not affected.

[0114] The system integration and debugging cycle is 3 working days.

[0115] Execution status of step ten:

[0116] After completing the joint commissioning test, remove the test cables and grounding wire, and clean the inside of the cabinet (vacuum cleaning + lint-free cloth wiping). Install the cabinet door and check that the door lock opens smoothly and the sealing strip is intact. The cabinet is packaged in a wooden crate with shock-absorbing foam, and comes with a factory test report (including insulation test, withstand voltage test, and joint commissioning record), electrical schematic diagram, wiring diagram, operation and maintenance manual (including pre-charge circuit debugging instructions), and product certificate.

[0117] The packaging cycle is 1 working day.

[0118] Manufacturing cycle statistics:

[0119] From design confirmation to product delivery, the total cycle is 25 working days. Compared to the traditional "one ship, one design" model (approximately 42 working days), the manufacturing cycle is shortened by about 40%.

[0120] The factory inspection results are shown in Table 1:

[0121] Table 1

[0122]

[0123] Example 2: Manufacturing of DC power distribution board for a coastal cargo ship

[0124] To further verify the versatility and inventiveness of the process of this invention, a 5,000-ton coastal cargo ship was selected as the application object. The ship is equipped with a 2,000 kWh battery pack as the main power source, a 200 kW photovoltaic power generation system, two 800 kW propulsion motors, and a 150 kW daily load.

[0125] Traditional manufacturing process (comparison group):

[0126] The design employed a non-standard, customized approach, with electrical design taking 12 working days. The cabinet used a welded frame, with busbars manually bent and punched on-site. The manual bending angle error reached ±3°, and the hole position deviation was ±1.5mm, resulting in two connection hole deviations requiring rework and enlargement during assembly. The laminate was cut and cold-punched using ordinary machinery, resulting in frayed and layered cut edges. No impregnation insulation treatment was applied, leading to one breakdown during the overall withstand voltage test, necessitating rework and re-insulation treatment. There were no pre-charge circuit installation specifications or verification procedures. The total manufacturing cycle was 58 working days.

[0127] Manufacturing process of this invention (experimental group):

[0128] Utilizing standardized modular selection, the design process takes only 3 working days. High-precision CNC busbar machining ensures successful assembly on the first attempt. After laminated insulation reinforcement, the withstand voltage test passed on the first try. The pre-charge circuit undergoes three levels of verification (step five: pre-verification → step six: standard installation → step nine: joint debugging confirmation), demonstrating reliable pre-charge functionality. The total manufacturing cycle is 32 working days, 44.8% shorter than traditional processes. Factory inspection passed on the first attempt, with no rework required.

[0129] Comparison conclusion:

[0130] This invention significantly shortens the design and manufacturing cycles, reduces on-site rework through parametric processing and module pre-assembly, and improves the withstand voltage test pass rate through insulation reinforcement treatment, demonstrating the innovative advantages of this invention's process in terms of efficiency improvement and quality assurance.

[0131] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A modular manufacturing process for a DC power distribution board for new energy ships, characterized in that, Includes the following steps: Step 1: Based on the configuration requirements of the ship's power system, the DC switchboard is divided into several standard functional modules, including DC bus module, lithium battery charging and discharging access module, new energy power generation access module, propulsion frequency converter output module, daily inverter output module, energy management control module and insulation monitoring module. The standard installation dimensions, electrical interface forms and communication protocols of each module are determined to form a standard module library. Step 2: Assemble the cabinet using standardized cabinet frame profiles and partitions to form a main cabinet frame with multiple independent compartments, and install removable moisture-proof components at the bottom of the cabinet. Step 3: Based on the voltage level and current carrying capacity requirements of the DC distribution board, calculate and determine the cross-sectional area and insulation spacing of the DC positive and negative busbars, and use a CNC busbar processing machine to perform parametric processing and surface treatment on the copper busbars; Step 4: Cut, drill holes, and impregnate the laminated insulating components, and test their insulation performance; Step 5: Perform pre-assembly and graded aging tests on the power devices and circuit board assemblies in each functional module; Step Six: Assemble the pre-installed and tested functional modules according to the compartment positions determined in Step Two. The DC side of the power module is connected to the DC busbar through a DC switch assembly, and the AC side is equipped with a pre-charge circuit. Step 7: Perform layered wiring inside the cabinet, measure the contact resistance at the busbar connection, and complete the wiring verification, continuity and insulation resistance test; Step 8: Perform insulation testing and dielectric strength testing; Step 9: Connect to the simulation test platform for system integration testing, including pre-charging timing verification, energy management scheduling function verification, and short-circuit protection coordination testing; Step 10: Clean, package, and include the factory technical documents with the cabinet.

2. The modular manufacturing process of a DC power distribution board for new energy ships according to claim 1, characterized in that, In step one, the DC bus module adopts a distributed segmented bus structure. The left DC bus consists of several DC bus unit segments, and each pair of adjacent DC bus unit segments is connected by a DC circuit breaker. The right DC bus consists of several DC bus unit segments, and each pair of adjacent DC bus unit segments is connected by a DC circuit breaker. The two busbars are connected by a bus tie switch.

3. The modular manufacturing process of a DC power distribution board for new energy ships according to claim 1, characterized in that, In step one, the power ratings of each module in the standard module library are configured in a series from 5.5kW to 355kW.

4. The modular manufacturing process of a DC power distribution board for new energy ships according to claim 1, characterized in that, In step two, the moisture-proof component includes a removable storage box containing a desiccant. An air inlet is opened at the front of the storage box, and a honeycomb mesh panel is installed on the top. The dried air is discharged through the ventilation and exhaust holes on the top of the cabinet.

5. The modular manufacturing process of a DC power distribution board for new energy ships according to claim 1, characterized in that, In step three, the bending angle error of the copper busbar processing shall not exceed ±1°, and the hole positioning error shall not exceed ±0.5mm; the surface treatment process includes pickling to remove the oxide layer → grinding to remove burrs → coating a conductive protective layer → drying and curing. The conductive protective layer is a tin-plated layer or a silver-plated layer with a plating thickness of 8~15μm.

6. The modular manufacturing process of a DC power distribution board for new energy ships according to claim 1, characterized in that, In step four, the laminated insulation components are made of epoxy glass cloth laminate. The cutting is done with silicon carbide abrasive wheel and water cooling. The hole processing adopts hot punching process. The board is preheated at 100~120℃ and the die gap is 10%~15% of the thickness of the laminate. The impregnation insulation treatment includes: pre-baking at 100±5℃ for 3~4 hours, cooling to 40~50℃ and immersing in epoxy resin insulating varnish, drying for 30~60 minutes, and curing at 100±5℃ for 4~5 hours.

7. The modular manufacturing process of a DC power distribution board for new energy ships according to claim 1, characterized in that, In step five, the graded aging test includes: the first-level aging test is to run continuously for 4 to 8 hours under the conditions of 1.1 times the rated voltage and an ambient temperature of 40 to 50°C; the second-level aging test is a pre-test of the control module's communication function to verify the reliability of data interaction between the CAN, RS485, and Ethernet communication interfaces.

8. The modular manufacturing process of a DC power distribution board for new energy ships according to claim 1, characterized in that, In step six, the pre-charging circuit includes a pre-charging contactor and a pre-charging resistor. The pre-charging contactor is connected in parallel with the main contactor, and the pre-charging resistor is connected in series in the pre-charging contactor branch. When the module is put into operation, the pre-charging contactor is first closed to charge the energy storage capacitor with current limitation. When the capacitor voltage reaches more than 90% of the bus voltage, the main contactor is closed and the pre-charging branch is disconnected.

9. The modular manufacturing process of a DC power distribution board for new energy ships according to claim 1, characterized in that, In step seven, the busbar connection is tightened to the set torque using a torque wrench, and the contact resistance is measured using a micro-ohmmeter. If the contact resistance exceeds the set threshold, the surface treatment and tightening operation are repeated. The control signal line and communication cable are kept at a distance of not less than 100mm from the power cable. The signal line is a shielded cable, and the shielding layer is grounded at a single point on the control end.

10. The modular manufacturing process of a DC power distribution board for new energy ships according to claim 1, characterized in that, In step eight, insulation testing includes measuring the insulation resistance between the positive and negative terminals of the DC busbar and between the positive and negative terminals and ground using a 500V or 1000V megohmmeter. The insulation resistance value should not be less than 20MΩ. The dielectric strength test involves applying an AC withstand voltage of 1000V plus twice the rated voltage between the DC busbar and ground for 1 minute without any breakdown or flashover.

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