Rail Vehicle Drive System Multi-System Adaptability
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Solution Overview
Problem
Existing drive systems for rail vehicles are not fully multi-system capable, as they require a large number of mechanical switches to reconfigure for operation on 3kV mains DC voltage, limiting their ability to operate on all four rail systems with direct feeding into an intermediate voltage circuit.
Innovation Solution
A drive system with a line-side infeed system divided into two partial converter systems, each with AC/AC converters and a medium-frequency transformer system, allowing for easy reconfiguration by short-circuiting the AC/AC converters using a filter inductor and switching device to supply power from one partial converter system to another, enabling operation on different mains voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the drive system uses a large number of mechanical switches to reconfigure for 3kV mains DC voltage operation, then the system can operate on different mains voltages, but the mechanical complexity and device complexity increase significantly
Solution Approach 1:
The patent replaces mechanical switches with a filter inductor and switching device to create an electrical short-circuit connection between the two partial converter systems. This substitution eliminates the need for mechanical reconfiguration while enabling the same voltage adaptation function, thereby reducing mechanical complexity while maintaining multi-system capability.
Solution Approach 2:
The filter inductor and switching device serve multiple functions: they enable short-circuiting of AC/AC converters for DC voltage operation, allows power transmission between partial converter systems, and maintain system adaptability to different mains voltages. This multi-functionality reduces the need for dedicated mechanical switches for each reconfiguration scenario.
2Productivity
If the AC/AC converters are short-circuited using a filter inductor and switching device, then power can be transmitted from one partial converter system to another, but the system requires precise control to generate opposing DC voltages
Solution Approach 1:
The control system continuously monitors the DC voltage outputs of both partial converter systems and adjusts their operation to maintain equal amplitude with opposite polarity. This feedback control ensures that when the systems are connected in parallel through the filter inductor, the voltages complement each other, enabling efficient power transmission while simplifying the overall control requirements through automatic voltage balancing.
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 system achieves full multi-system capability with reduced mechanical complexity, allowing seamless operation on various mains voltages by generating opposing DC voltages in each partial converter system and regulating current through a short-circuit loop, ensuring efficient power transmission.
Implementation Method 1
a medium-frequency transformer system (36, 38) with k medium-frequency transformers (36, 38) each with n primary windings (40) and j secondary windings (42)
Implementation Method 2
short-circuiting the AC/AC converters by means of a filter inductor (50) and switching device (62)
Data Source
Figure 1
Figure 2~4
Figure 5~6
AI summary
The invention relates to a drive system for a rail vehicle. According to the invention, said drive system has a line-side supply system comprising two half-converter systems (2, 4) and a load-side self-commutated power converter (6) with an output-side three-phase motor (8). Each half-converter system (2, 4) comprises n AC/AC converters (321´...´ 32n; 341 ´...´ 34n), a middle-frequency transformer system (36, 38) comprising k middle-frequency transformers that each comprise n primary windings (40) and j secondary windings (42), and a load-side power converter system (44, 46) with at least one AC/DC converter (48). The 2n AC/AC-converters ( 321 ´...´ 32n; 341 ´...´ 34n) of the two half-converter systems (2, 4) are electrically mounted in series. A respective transformer system (2, 4) of the two half- converter systems (2, 4) couples the n AC/AC converters (321 ´..´ 32n; 341 ´...´ 34n) of a respective half-converter system (2, 4) to a load-side power converter system (6). The series connection of the 2n AC/AC converters (32i, 32n; 341 ´...´ 34n) of the two half-converter systems (2, 4) can be electrically mounted in parallel with a filter throttle (50) by means of a switching appliance (62), and connections (10, 12, 14, 16) on the direct-voltage side, of the two partial power converter systems (2, 4), and the connections (20, 22) on the direct-voltage side, of the load-side self-commutated power converter (6) can be interconnected by means of a switching appliances unit (18) to which a direct line voltage is applied. In this way, a drive system is obtained for rail vehicles, that can be easily configured for each line voltage.