Boat Drive Fourth Quadrant Regeneration
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Solution Overview
Problem
Existing boat drives lack an efficient alternative method for charging batteries while in motion, particularly for sailing boats, as they rely on shore connections, internal combustion engine generators, or solar/wind power, which may not be available or sufficient.
Innovation Solution
A drive system for boats that includes an electric motor, propeller, and control device capable of operating in the fourth quadrant to regenerate flow energy from the water into electrical energy, allowing batteries to be charged while the boat is in motion, with a folding propeller design to minimize resistance and optimize energy conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the electric motor operates in the first or third quadrant to provide forward or reverse thrust, then propulsion function is achieved, but no electrical energy is generated for battery charging
Solution Approach 1:
The electric motor is designed to perform multiple functions: it can operate in the first quadrant to provide forward thrust, in the third quadrant for reverse thrust, and in the fourth quadrant to generate electrical energy by functioning as a generator. This multi-functionality allows the same motor to serve both propulsion and power generation purposes, resolving the contradiction between maintaining propulsion capability and enabling battery charging.
2Loss of energy
If a folding propeller is used to minimize resistance during sailing, then energy efficiency is improved, but the propeller must be mechanically complex to fold and unfold
Solution Approach 1:
The propeller is designed as a folding propeller that can dynamically change its configuration. During sailing, the propeller blades fold back to minimize water resistance and improve energy efficiency. When the electric motor needs to operate as a generator, the propeller unfolds to its operational position. This dynamic adaptability allows the system to optimize for different operating conditions, accepting the mechanical complexity as a trade-off for significant energy savings.
3Power
If the product of propeller pitch and rotational speed is kept less than relative flow velocity in fourth quadrant operation, then electrical energy generation is optimized, but the control requirements become more stringent
Solution Approach 1:
The control device continuously monitors the operating conditions and adjusts the propeller rotational speed to maintain the optimal relationship where the product of propeller pitch and rotational speed remains less than the relative flow velocity. This feedback control ensures that the electric motor operates in the fourth quadrant at the optimal point for electrical energy generation, automatically adapting to changing sailing conditions and compensating for the increased control requirements.
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
Enables the conversion of kinetic energy from sailing or boat motion into electrical energy for battery charging, providing a sustainable and efficient power solution for sailing boats, even in areas without shore connections, by operating the electric motor in the fourth quadrant to harness flow energy.
Implementation Method 1
the control device (34) is configured to operate the electric motor (4) in the fourth quadrant such that it regenerates flow energy from the water surrounding the propeller (2), which is transferred to the electric motor (4) via the propeller (2), into electrical energy
Data Source
Figure 1
Figure 2
AI summary
The present invention relates to a drive (1) for a boat, in particular for a sailboat, comprising an electric motor (4) which is designed for operation in the first quadrant and in the fourth quadrant, a propeller (2) connected to the electric motor (4) and a control device, wherein the control device is designed to operate the electric motor (4) in the fourth quadrant in such a way that it regenerates flow energy from the water surrounding the propeller, which flow energy is transmitted to the electric motor via the propeller, into electrical energy and that a product of a propeller pitch of the propeller (2) and a rotational speed of the propeller (2) is less than a relative flow velocity between the water and the drive.