Adaptive Feed-Forward Compensation for Traction System Disturbances
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Solution Overview
Problem
Existing methods for suppressing second harmonic disturbances in traction systems on railway vehicles are inefficient across all operating points and require physical filters that increase weight, space, and power losses.
Innovation Solution
An adaptive feed-forward compensation technique that measures and calculates a second periodic disturbance to minimize the total influence of first and second periodic disturbances, allowing for optimized suppression without the need for physical filters, by applying an adaptive algorithm to the system's measurements and adjusting parameters for improved performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If physical second harmonic filters are installed in the DC intermediate link, then the voltage oscillations are suppressed effectively, but the system experiences increased weight, space requirements, and power losses
Solution Approach 1:
The patent replaces physical second harmonic filters (mechanical/electrical components) with a control-based solution using adaptive feed-forward compensation. The controller calculates and applies a compensating signal to counteract the second harmonic disturbances, eliminating the need for physical filters and their associated weight, space, and power losses.
Solution Approach 2:
The patent changes the operating parameters of the converter by dynamically adjusting the modulation index and switching patterns based on detected second harmonic disturbances. This allows the system to suppress voltage oscillations through parameter optimization rather than physical filtering components.
2Reliability
If existing suppression methods are applied, then some operating points are improved, but suppression is not optimized across all operating points
Solution Approach 1:
The patent implements a dynamic control solution where the controller continuously adapts its behavior based on the current operating point. The adaptive feed-forward compensation algorithm adjusts its parameters in real-time to optimize suppression performance across the entire operating range, making the system versatile and effective under all conditions.
Solution Approach 2:
The patent employs feedback mechanisms where the controller monitors the actual second harmonic disturbances and uses this information to adjust the compensating signals. This closed-loop approach ensures optimal suppression performance across all operating points by continuously adapting to changing system conditions.
3Object-generated harmful factors
If physical filters are used to suppress second harmonics, then torque pulsations are reduced, but the system complexity and cost increase
Solution Approach 1:
The patent replaces complex physical filtering systems with a simpler control-based solution. The adaptive feed-forward compensation is implemented through software algorithms in the controller, eliminating the need for additional physical components and reducing overall system complexity while effectively suppressing torque pulsations.
Solution Approach 2:
The patent creates a virtual model of the second harmonic disturbances through signal processing and uses this model to generate compensating signals. This software-based approach copies the disturbance characteristics and counteracts them without requiring physical filters, simplifying the system architecture.
Data Source
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AI summary
A method for suppressing the influence of a first periodic disturbance (d) upon a quantity (y) in a traction system on board a railway vehicle comprises the steps of measuring said quantity, applying an adaptive algorithm (K) on the result of the measurement of said quantity calculating a second periodic disturbance (u) which when applied to the system would make the total influence of said first and second periodic disturbances upon said quantity to a minimum, and applying said second periodic disturbance (u) to influence said quantity (y).