Variable Power Take-Off System With Electric Generating Capacity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current power take-off systems in vehicles lack flexibility in operation, as they either provide rotational power or electrical power but not both efficiently, and do not allow for variable speed control of the power take-off output shaft.
Innovation Solution
A power take-off system with a controller that receives inputs from a human-machine interface to select between variable speed power take-off mode and electrical power generation mode, using an internal combustion engine to drive an electrical generator and an electrical machine to provide power to a high voltage bus, while also controlling a power take-off brake to manage rotational power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the power take-off system operates in traditional mode providing only rotational power, then the structural complexity is reduced, but the adaptability and versatility are limited
Solution Approach 1:
The power take-off system is designed to perform multiple functions through a single integrated mechanism. The system can operate in three distinct modes: traditional rotational power take-off mode, electrical power generation mode, and hybrid mode providing both rotational and electrical power simultaneously. This multi-functionality is achieved by integrating an electrical generator, electrical machine, and brake system with the traditional rotational power take-off shaft, allowing the system to adapt to different operational requirements without requiring separate systems for each function.
Solution Approach 2:
The system incorporates variable speed control capability through the integration of an electrical machine that can operate as a motor or generator. This allows the rotational speed of the power take-off output shaft to be independently controlled and varied according to operational needs, rather than being fixed by the engine speed alone. The dynamic control is managed through a controller that receives operator input and adjusts the electrical machine operation accordingly, enabling smooth speed variation across a wide range.
2Productivity
If the system provides both electrical and rotational power simultaneously, then the productivity is improved, but the loss of energy increases
Solution Approach 1:
The system incorporates a controller that continuously monitors operational parameters and adjusts the operation of the electrical generator and electrical machine accordingly. The controller receives operator input through a human-machine interface and automatically manages the power distribution between rotational and electrical outputs. This feedback control ensures that the system operates at optimal efficiency points by adjusting the load on the electrical generator and the power conversion in the electrical machine based on actual demand, minimizing energy losses while maintaining the desired dual power output.
Solution Approach 2:
The system utilizes variable speed operation of the electrical machine to optimize energy efficiency. By changing the operating parameters of the electrical machine (speed, torque, power conversion ratio), the system can adapt to different power demand conditions. When both rotational and electrical power are required, the electrical machine operates as a motor driven by the electrical generator, and its operating parameters are continuously adjusted to maintain optimal efficiency across varying load conditions, rather than operating at fixed parameters that would result in energy waste.
3Ease of operation
If variable speed control is implemented for the power take-off output shaft, then the ease of operation is improved, but the device complexity increases
Solution Approach 1:
The electrical machine serves as an intermediary device between the engine and the power take-off output shaft, enabling variable speed control. Rather than directly coupling the engine to the output shaft with fixed speed, the electrical machine acts as a mediator that can independently control the rotational speed of the output shaft while being driven by the engine through the electrical generator. This intermediary approach simplifies the control system compared to mechanical variable speed mechanisms, as the electrical machine can be precisely controlled through electrical signals from the controller, providing smooth and accurate speed adjustment.
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 efficient generation and distribution of both electrical and rotational power, allowing for variable speed control of the power take-off output shaft and maximizing electrical power generation without rotational power in selected modes.
Implementation Method 1
drive the electrical generator to provide electrical power to a high voltage bus
Implementation Method 2
drive the electrical machine to provide electrical power to the high voltage bus
Implementation Method 3
actuate a power take-off brake to stop rotation of the power take-off output shaft
Data Source
AI summary
A power take-off system and method is provided for a vehicle that includes an internal combustion engine, an electrical generator, an electrical machine, a power take-off summing planetary and a power take-off brake. The power take-off system includes a controller and a human-machine interface. The controller is configured to receive an input from the human-machine interface to select one of a variable speed power take-off mode, an electrical power generation mode, and a full power fixed ratio power take-off mode of operation. In the variable speed power take-off mode, electrical power from the electrical generator and rotational power by the power take-off system are output, and the electrical machine receives electricity and provides rotational power. In the electrical power generation mode, the electrical generator and the electrical machine both provide electrical power. In the full power fixed ratio mode, no electrical power is provided.