Unidirectional Energy Train for Range Extender
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Solution Overview
Problem
Existing energy transmission trains for range extender modules in electric vehicles are costly, heavy, and space-consuming due to the need for bidirectional inverters and high-torque generators, making them impractical for smaller vehicles.
Innovation Solution
A unidirectional energy transmission train consisting of an internal combustion engine, alternator, rectifier, and microprocessor-controlled DC/DC converter, eliminating the need for a bidirectional inverter and utilizing a simple passive rectifier and commercially available starter motor, with the DC/DC converter providing voltage control for a high-voltage battery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a bidirectional inverter module is used to enable the generator to operate in reverse as a motor for starting the internal combustion engine, then the system can achieve bidirectional power flow, but the device complexity, cost, weight, and installation space increase significantly
Solution Approach 1:
The system is divided into separate functional components: a dedicated starter motor for engine starting and a unidirectional inverter for power conversion. This segmentation eliminates the need for a complex bidirectional inverter, reducing device complexity while maintaining the ability to start the engine and convert power unidirectionally.
Solution Approach 2:
The unidirectional inverter is designed to perform multiple functions: converting DC from the battery to AC for the generator during normal operation, and potentially supporting engine starting when combined with the starter motor. This multi-functionality reduces the need for separate specialized components.
2Reliability
If the generator and inverter module are designed for high starting torque of the internal combustion engine, then the engine can be started reliably, but the weight and installation space increase
Solution Approach 1:
The starting function is separated from the generator function. A dedicated starter motor handles the high-torque engine starting requirement, allowing the generator to be designed for lower power and weight while maintaining reliable engine starting capability.
Solution Approach 2:
The system uses a simple, inexpensive starter motor that can be replaced if needed, rather than designing a complex, heavy generator-inverter system optimized for starting. This approach prioritizes cost-effectiveness and weight reduction while maintaining starting reliability.
3Use of energy by moving object
If a synchronous generator is used for the alternator, then the generator can operate efficiently, but an angular position sensor is required which increases costs
Solution Approach 1:
The system uses a simple permanent magnet synchronous generator without expensive angular position sensors. While this may slightly reduce control precision compared to sensor-based systems, it significantly reduces costs and complexity while maintaining sufficient efficiency for the application.
4Adaptability or versatility
If a bidirectional inverter module is used, then the system can convert power bidirectionally, but the installation space and weight increase which is not practicable for smaller electric vehicles
Solution Approach 1:
The power conversion system is segmented into a unidirectional inverter and a separate starter motor. This eliminates the need for a large bidirectional inverter, significantly reducing installation space and weight while maintaining the essential functionality of power conversion and engine starting.
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 configuration reduces costs, weight, and installation space, allowing for a more compact and affordable solution suitable for small city vehicles, while eliminating the need for angular position sensors and high-starting-current components.
Implementation Method 1
an alternator which is driven by the internal combustion engine
Implementation Method 2
a rectifier which is electrically connected to the alternator
Implementation Method 3
a downstream unidirectional microprocessor-controlled DC/DC converter for feeding an electric high-voltage battery
Data Source
AI summary
The invention relates to an energy transmission strand for a range extender module comprising a sequence from an internal combustion engine (7), an alternating current generator (8) mechanically driven thereby and an inverter (10) electrically connected thereto having a downstream, unidirectional DC/DC converter (11) for supplying an electrical load, wherein the internal combustion engine (7) has an electrical starter motor (5) of its own.