Ship Electric Motor Generator Mode for Power Reliability

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Solution Overview

Problem

Ships with combined electric and internal combustion engine propulsion systems face operational reliability issues due to potential failures in power generation units, leading to disruptions in the electrical system and blackouts, especially when transitioning between propulsion modes.

Innovation Solution

The electric motor can be operated in generator mode to feed electrical energy back into the vehicle electrical system, allowing for energy conversion from mechanical energy and providing energy reserves during power generator or internal combustion engine failures, with a converter and control system ensuring seamless switching and precise energy flow management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple independent power generation units are used to achieve high operational reliability, then the electrical system can maintain power supply, but the complexity of the system increases and the risk of disruptions remains

Engineering Contradiction:
Improveoperational reliabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The electric motor is designed to perform dual functions: it operates as a motor during normal propulsion and as a generator during power generation unit failures. This multi-functionality eliminates the need for separate standby power generation equipment, reducing system complexity while maintaining reliability. The electric motor serves both propulsion and power generation needs, making the system more efficient and less complex.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Use of energy by moving object

If electric motors are used as main engines for lower speeds, then fuel efficiency is improved, but the ship cannot achieve maximum speed without auxiliary internal combustion engines

Engineering Contradiction:
Improvefuel efficiencyVSAvoidmaximum speed
Core Design Contradiction:
Use of energy by moving objectVSSpeed

Solution Approach 1:

The propulsion system dynamically adapts its configuration based on operational requirements. At lower speeds, the electric motors operate independently for fuel-efficient cruising. At higher speeds, the internal combustion engine dynamically couples to the propeller shafts to provide additional propulsion power. The system transitions between different operational modes (electric-only, hybrid, combustion-only) to optimize both fuel efficiency and speed performance.

Inventive Principle:
Principle #15Dynamics

3Reliability

If the electric motor is switched from motor mode to generator mode during power generation unit failure, then operational reliability is improved, but the switching time and control complexity increase

Engineering Contradiction:
Improveoperational reliabilityVSAvoidswitching time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The control system is pre-configured with switching logic that prepares the electric motor for rapid mode transition. The converter and control system maintain readiness to switch from motor to generator mode, minimizing response time during power generation unit failures. The system has pre-established control pathways and energy flow configurations that enable quick adaptation without extensive reconfiguration delays.

Inventive Principle:
Principle #10Preliminary action

4Adaptability or versatility

If the converter and control system manage energy flow between electric motor and on-board power supply, then energy distribution flexibility is improved, but the device complexity increases

Engineering Contradiction:
Improveenergy distribution flexibilityVSAvoidcontrol system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The converter acts as an intermediary device that manages energy flow between the electric motor and the on-board power supply. It provides bidirectional energy conversion and control, enabling the system to operate in different modes (motor mode, generator mode, power supply support) while maintaining electrical system stability. The converter simplifies the control architecture by centralizing energy management functions in a single interface device.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution enhances operational reliability by preventing blackouts, optimizing energy distribution, and maintaining power supply during failures, while also allowing for flexible energy use and efficient operation of the propulsion system.

Implementation Method 1

The electric motor can also be operated as a generator, wherein in generator mode it can be connected to the on-board power supply via an electrical line to feed electrical energy into the on-board power supply. The mechanical energy delivered to the shaft system by the at least one internal combustion engine can therefore be converted into electrical energy with the help of the electric motor in generator mode

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP1894836B1Ship with electric propulsion and auxiliary propulsion using combustion engines
Publication Date: 2015.12.02 SIEMENS AG
  • EP1894836B1 patent drawingFigure 1
  • EP1894836B1 patent drawingFigure 2~3
  • EP1894836B1 patent drawingFigure 4

AI summary

In a ship with - at least one electric motor (2) as the main engine for propelling the ship, wherein the electric motor (2) drives a shaft system (3) which is coupled to a ship's propeller (3), - at least one internal combustion engine (5) which can be coupled to the shaft system (3), in particular a gas turbine or one or more diesel engines, as an additional drive for achieving the maximum speed of the ship (1), - an on-board electrical system (10) for supplying electrical consumers (20) of the ship with electrical energy and - generators (9) for generating electrical energy for the at least one electric motor (2) and for the on-board electrical system (10), the operational reliability can be increased in that the at least one electric motor (2) can also be operated as a generator, wherein in generator mode it can be connected to the on-board electrical system (10) via an electrical line (11) for feeding electrical energy into the on-board electrical system.