Description

Low-speed variable frequency permanent magnet synchronous propulsion motor

Revolutionary solution for direct-drive propulsion systems for ships

Core Product Positioning: A low-speed, high-torque permanent magnet synchronous motor specifically designed for modern marine electric propulsion systems. Employing a “gearbox-less direct drive” design concept, it achieves direct coupling between the propeller and the motor, providing a highly efficient, precise, and reliable propulsion power core for twin-propeller vessels.

In-depth Technical Analysis

1. Revolutionary Breakthrough in Direct Drive Technology

Structural Advantages:

Zero intermediate transmission links: The motor output shaft is directly connected to the propeller shaft via a high-precision flange.

Simplified Structure: Compared to the traditional “diesel engine + gearbox + shaft system” solution, the number of components is reduced by 60%.

Space Optimization: Axial length is shortened by 40%, providing greater flexibility for ship design.

Performance Indicators:

Transmission Efficiency: 98.5% (Traditional gearbox transmission is typically 95-96%)

Mechanical Losses: Reduced to 1/3 of traditional systems

Power Density: 35% higher than asynchronous motors of the same power.

2. Core Technology of Permanent Magnet Synchronous Motor

Magnetic Circuit Design:

Utilizes neodymium iron boron permanent magnet material, achieving a magnetic energy product of 45 MGOe.

V-shaped magnet arrangement increases air gap magnetic flux density to 1.2T.

Built-in rotor structure avoids the risk of permanent magnet detachment.

Control Characteristics:

Power factor > 0.95 across the entire speed range

Dynamic response time < 50ms

Overload Capacity: 150% rated torque for 2 minutes

Complete Technical Parameter System

Model Specification Matrix

Application scenarios	Recommended frame size	Power range	Typical speed	Installation method
small workboat	132-315	7.5-200kW	100-300rpm	B3
Inland waterway cargo ships	355-560	200-1500kW	50-200rpm	B3/V1
Coastal ferries	630-800	1500-3000kW	30-150rpm	V1
ocean-going vessels	H1000-H1400	3000-5000kW	5-100rpm	V1

Detailed Performance Parameters

Electrical Parameters:
Rated Voltage: 380V/690V/3300V/6600V (multiple options available)
Frequency Range: 0-100Hz stepless adjustment
Current Harmonics: THD <3% (under full load conditions)
Efficiency Curve: >94% efficiency within 20%-120% load range

Mechanical Parameters:
Maximum Torque: 600kNm (instantaneous peak up to 750kNm)
Speed ​​Accuracy: ±0.1rpm (steady-state operation)
Axial Runout: <0.5mm (full load operation)
Radial Runout: <0.3mm (ISO1940 G2.5 balance grade)

Professional Cooling System Configuration

Air-cooled System (IC416) – Applicable Power <500kW
Technical Features:
Independent forced ventilation design, adjustable airflow
Inlet air filtration grade G4
Outlet air temperature monitoring and protection
Noise Level <75dB(A) @ 1m
Application Advantages:
No external cooling water system required
Maintenance interval up to 8000 hours
Suitable for ships with limited engine room space
Water Cooling System (IC71W) – Applicable power > 500kW
Technical Features:
Closed-loop water cooling, heat exchange efficiency > 85%
Cooling water temperature difference control: ΔT < 10°C
Water pressure loss: < 0.5 bar @ rated flow rate
Leakage detection and automatic alarm
System Configuration:
Main cooling circuit: Ethylene glycol solution (antifreeze and anti-corrosion)
Secondary heat exchange: Connected to the central cooling system
Flow rate requirement: 2-40 L/s (depending on power rating)
Detailed Explanation of Protection and Insulation Ratings
Protection Rating Selection Guide
IP54 Standard Configuration:
Dustproof rating: Prevents solids with diameter > 1 mm from entering
Waterproof rating: Splash-proof, unaffected by water spray from all directions
Suitable for: Dry engine room environment
IP55 Enhanced Configuration:
Spray protection: 6.3 mm nozzle, 3m distance
Salt spray test: Passed 500 hours of neutral salt spray test
Suitable for: General engine room environment
IP56 marine-grade configuration:
Protection against strong water jets: 12.5mm nozzle, 3m distance
Temporary immersion: Short-term submersion does not affect performance
Suitable for: Engine room bottom, vessels in harsh sea conditions
Insulation system technical parameters
H/F class insulation:
Heat resistance rating: 180°C (stator winding)
Temperature rise limit: 125K (stator winding)
Expected life: >50,000 hours
F/B class insulation Surface: Heat resistance rating: 155°C (rotor permanent magnet) Temperature monitoring: Built-in PT100 RTD Overload capacity: No temperature rise exceeding the limit under 10% continuous overload Installation and alignment technical requirements B3 foot mounting (power <2000kW) Foundation requirements: Foundation flatness: <0.1mm/m Anchor bolt preload: ±5% control accuracy Vibration isolation: Optional elastic base V1 flange mounting (power >2000kW) Alignment accuracy standard: Shaft alignment deviation: <0. 0.05mm
Angle Deviation: <0.05°/m
Flange Face Runout: <0.03mm
Installation Tool Kit Includes:
Dedicated Alignment Tool
Hydraulic Tensioning Tool
Torque Wrench and Calibration Certificate
Control System Integration Solution
Variable Frequency Drive Matching
Recommended Inverter Specifications:
Voltage Rating Matches Motor Rated Voltage
Capacity Margin: 1.2-1.5 times Motor Rated Current
Control Algorithm: Field-Oriented Control (FOC)
Communication Interface: CANopen/Profibus/Modbus TCP
Propulsion Control Function
Basic Control Modes:
Speed ​​Control Mode: Accuracy ±0.1%
Torque Control Mode: Accuracy ±1%
Power Limiting Mode: Automatic Load Sharing
Advanced Function Options:
Dynamic Positioning (DP) Interface
Load Balancing Algorithm
Emergency Backup Mode
Energy Efficiency Optimization Strategy
Economic Benefit Quantitative Analysis
Investment Cost Comparison (Taking a 3000kW System as an Example)

project	Traditional system	Direct-drive permanent magnet system	Savings
Reduction gearbox	$250,000	$0	$250,000
Foundation and Installation	$80,000	$50,000	$30,000
Shaft length	15m	9m	Spatial value
Total investment	$330,000	$50,000	$280,000

Operating Cost Savings

Fuel Savings:
Transmission Losses Reduction: 3-5%
Annual Fuel Savings: 60-100 tons (based on 5000 hours/year)
Annual Cost Savings: $30,000-$50,000
Maintenance Costs:
Gearbox Maintenance: $15,000/year → $0 Bearing replacement cycle: Extended from 3 years to 8 years Annual maintenance cost reduction: $20,000 Typical application case studies Case 1: 4500-ton coastal cargo ship Configuration: Motor model: H1000-3500kW Speed: 85rpm Cooling method: IC71W Protection rating: IP56 Operating data: Annual operating time: 6500 hours Fuel consumption rate: Reduced by 4.2% Vibration level: <2.8mm/s (far below IMO standard) Availability: 99.7% Case 2: Ro-Ro passenger ship with twin propellers System configuration: 2×H800-2800kW motors V1 flange mounting F/B insulation class Performance: 40% improvement in port maneuverability; Passenger comfort rating improved by 2 levels; Noise levels: Engine room 65dB, passenger cabin 45dB. Quality Control and Certification System: Manufacturing Process Control: Key Process Control Points: Stator winding: Automatic winding machine, tension control ±2%; Vacuum impregnation: Vacuum degree <10Pa, paint content >75%; Dynamic balancing: G2.5 grade, on-site rebalancing possible. Testing Items: Includes but is not limited to: 48-hour no-load test; 72-hour load test; Thermal cycling test (-25°C to +80°C); Vibration spectrum analysis. International Certifications: Classification society certifications: ABS, DNV, CCS, BV, etc.; Environmental certification: IMO Tier III compliant; Safety certification: ATEX Zone 2 (explosion-proof optional). Quality System: ISO9001:2015