Rail Vehicle Drive Assembly Seamless Energy Source Switching
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Solution Overview
Problem
Existing drive arrangements for rail vehicles face challenges in achieving rapid and stable switching between battery operation and overhead line operation, leading to potential instability and disruptions in energy supply during mode transitions.
Innovation Solution
A drive arrangement with a converter and a DC voltage controller, controlled by a device that operates either or both as voltage sources for the DC voltage intermediate circuit, allowing for simultaneous operation with different target voltages to ensure stable supply and seamless transitions between energy sources, including the use of a control device to manage switching and operating modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the converter and DC voltage controller are operated simultaneously as voltage sources during switchover mode, then the switching time between energy sources is reduced and continuous power supply is ensured, but control instability may occur due to conflicting voltage targets
Solution Approach 1:
The control device dynamically changes the target voltage parameter for the DC voltage controller during switchover mode, setting it to a value lower than the converter's target voltage. This parameter differentiation allows both voltage sources to operate simultaneously without conflict, enabling rapid switchover while maintaining control stability.
2Reliability
If only one voltage source (converter or DC voltage controller) is operated at a time, then control stability is maintained, but switching between energy sources causes interruptions and delays in power supply
Solution Approach 1:
The invention merges the operation of two voltage sources (converter and DC voltage controller) by allowing them to operate simultaneously during switchover mode. The control device coordinates both sources with differentiated target voltages, combining their outputs to ensure continuous power supply to the DC voltage intermediate circuit without interruptions or delays.
3Reliability
If the converter is deactivated during switchover to avoid control conflicts, then control stability is maintained, but the energy supply continuity is compromised
Solution Approach 1:
Instead of deactivating the converter, the control device changes the operational parameter (target voltage) of the DC voltage controller to be lower than the converter's target voltage during switchover mode. This allows both sources to remain active and contribute to power supply, ensuring continuity while avoiding control conflicts through parameter differentiation.
Data Source
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AI summary
A drive arrangement of a rail vehicle comprises at least one converter which can be connected to a power supply network at a first connection side and is connected to a DC link at a second connection side, a DC voltage controller which is connected to the DC link at a first connection side and to an internal power supply device at a second connection side, and a control device which is designed to operate either the converter or the DC voltage controller as the voltage source for the DC link in normal operation and to specify a target DC link voltage as the target voltage for the DC link.Furthermore, the control device is designed to operate the inverter and the DC voltage controller simultaneously in a switching mode, specifying different target voltages for the DC link to the inverter and the DC voltage controller.