Drive Unit Engine Starting via DC-DC Voltage Step-Up
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for starting internal combustion engines, such as diesel engines, in traction applications face challenges due to insufficient energy potential from starter batteries, particularly at low voltages, and temperature-dependent performance issues, leading to high battery currents and reliability concerns.
Innovation Solution
A drive unit comprising a power converter with dual inverters and a switching unit that allows the working machine to operate as both a motor and generator, utilizing an energy storage device to provide the necessary starting torque independently of the battery's energy potential, thereby eliminating the need for an auxiliary motor and minimizing the impact of temperature on battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a starter battery with low voltage (24V) is used to start the engine, then the battery can be smaller and lighter, but the energy potential is insufficient and high battery currents are required
Solution Approach 1:
The patent introduces a DC-DC converter as an intermediary device between the low-voltage battery and the high-voltage power converter. This converter steps up the voltage from 24V to the required higher voltage level, enabling the battery to provide sufficient energy potential without requiring high currents. The intermediary converter resolves the contradiction by transforming the electrical parameters between the two voltage levels.
Solution Approach 2:
The patent changes the voltage parameter through a DC-DC converter, transforming the battery output from low voltage (24V) to high voltage. This parameter transformation allows the battery to deliver the necessary energy potential for engine starting without requiring excessive current, thus resolving the contradiction between battery size/weight and energy potential.
2Adaptability or versatility
If a starter battery is used to support engine starting, then the vehicle electrical system can be supported, but the battery performance decreases at low temperatures and high currents are required
Solution Approach 1:
The DC-DC converter acts as a mediator that isolates the battery from the high-current demands of engine starting. By converting voltage before power delivery, the system reduces the current required from the battery, thereby improving starting reliability at low temperatures while maintaining the battery's ability to support the electrical system.
Solution Approach 2:
The patent replaces the direct electrical connection and high-current discharge mechanism with a controlled DC-DC conversion process. This substitution allows for optimized power delivery that maintains battery performance across temperature ranges while providing sufficient starting power.
3Reliability
If an additional auxiliary motor is used to provide starting torque, then the engine can be started reliably, but the device complexity increases
Solution Approach 1:
The patent makes the power converter and working machine multi-functional by enabling them to operate in both motor mode (providing starting torque) and generator mode (charging the battery). This eliminates the need for a separate auxiliary motor, as the existing power converter performs the function of both the auxiliary motor and the main drive controller, thereby reducing device complexity while maintaining starting reliability.
Solution Approach 2:
The patent merges the function of the auxiliary starting motor with the main power converter and working machine. By combining these functions into a single system that can operate bidirectionally (motor and generator modes), the patent eliminates the need for separate auxiliary components, reducing overall system complexity while ensuring reliable engine starting.
4Power
If a step-up converter is added to raise the battery voltage, then the energy potential is sufficient, but the device complexity and circuitry adaptation increase
Solution Approach 1:
The patent makes the power converter universal by designing it to function as both a DC-DC converter (for voltage step-up during starting) and a standard power converter (for normal operation). This multi-functionality eliminates the need for a separate step-up converter, providing sufficient energy potential while minimizing additional circuitry and complexity.
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
The solution enables reliable engine starting with reduced circuitry adaptation, independent of the battery's energy potential, and reduces the load on the vehicle's on-board network, while minimizing the influence of temperature-dependent battery performance.
Implementation Method 1
the first inverter (2) is designed to be able to be connected to a motor (54) on the AC voltage side and is connected to the intermediate circuit (6) on the DC voltage side
Implementation Method 2
the second inverter (4) is connected to the intermediate circuit (6) on the DC voltage side and can be connected to the working machine (50) on the output side
Implementation Method 3
the working machine (50) can be operated either as a motor or as a generator
Implementation Method 4
the working machine (50) can be operated either as a motor or as a generator
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to a drive unit for controlling an engine. In particular, the present invention relates to an improved controller for starting an internal combustion engine which is designed for driving a traction generator coupled to the engine. The disadvantage is known from the prior art that the potential energy made available by a battery during the process of starting an engine is not sufficient if the battery is designed only to provide a relatively low supply voltage, for instance. The problem addressed by the present invention is therefore that of providing an improved and simpler drive unit for controlling and starting an engine which makes reliable starting of the engine possible and thereby requires only a minimal circuit engineering adaptation to the existing engine and drive unit in a vehicle. The problem is solved with a drive unit (100) comprising: a current converter (20), which can be connected to a work machine (50) comprising an intermediate circuit (6) which can be coupled to a first inverter (2) and to a second inverter (4), wherein the first inverter (2) is designed to be connectable on the alternating current side to a motor (54) and is connected on the direct current side to the intermediate circuit (6) and wherein the second inverter (4) is connected on the direct current side to the intermediate circuit (6) and can be connected on the alternating current side to the work machine (50) and wherein the second inverter (4) is designed to control the work machine (50) in such a manner that the work machine (50) can be operated either as a motor or as a generator; a connection to at least one energy store (10); a switching unit (8, 13) which is connected to the current converter (20) wherein the switching unit (8, 13) can be operated in a first operating mode or in a second operating mode, wherein in the first operating mode the switching unit (8, 13) is designed to couple the current converter (20) to the at least one energy store (10) to allow an energy flow from the at least one energy store (10) via the switching unit (8, 13) to the intermediate circuit of the current converter (20), and wherein in the second operating mode the switching unit (8, 13) is designed to isolate the current converter (20) from the at least one energy store (10), wherein the drive unit (100) comprises an energy store charging unit (12) which can be connected to the current converter (20) to make energy available to the energy store (10).