Parallel DC-DC Converter Control for Uniform Current Sharing
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Solution Overview
Problem
DC-DC converter modules connected in parallel experience unequal loading and potential damage due to component part tolerances and aging effects, leading to varying output currents and powers, necessitating a solution for uniform current output and preventing excessive current rises.
Innovation Solution
A control device with a compensation unit that generates additional controlled variables for each module, considering individual properties like component tolerances, using prestored correction values to combine with existing controlled variables, ensuring identical output power and current across all modules.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If multiple DC-DC converter modules are connected in parallel to increase output power, then the output power is improved, but unequal loading and varying output currents occur due to component tolerances and aging effects
Solution Approach 1:
The patent applies parameter changes by introducing individual compensation variables for each converter module that adjust the controlled variables based on measured deviations. The control unit modifies operating parameters (controlled variables) for each module individually to compensate for tolerances and aging effects, ensuring uniform current distribution while maintaining increased output power from parallel connection
Solution Approach 2:
The patent implements feedback control by continuously measuring the actual output currents of individual converter modules and using these measurements to adjust the controlled variables. The control unit receives feedback on current deviations and dynamically modifies the operating parameters to maintain uniform loading across all parallel-connected modules
2Reliability
If individual controlled variables are provided for each DC-DC converter module to achieve uniform current output, then the uniformity of current distribution is improved, but the device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the control function into module-specific controlled variables and compensation variables for each converter module. The control unit processes each module individually with dedicated control parameters, allowing uniform current distribution while keeping the overall control structure organized and manageable through modular segmentation
3Measurement precision
If compensation variables are determined using prestored correction values, then the compensation accuracy is improved, but the manufacturing complexity and cost increase
Solution Approach 1:
The patent applies preliminary action by determining and storing compensation variables in advance during the manufacturing process. The compensation variables are calculated and stored in memory before the converter operates, based on measured characteristics of each individual module. This preliminary determination ensures high compensation accuracy during operation without requiring complex real-time calculations or additional manufacturing steps
Data Source
AI summary
The invention relates to enhanced adjusting of the control variables for a DC-DC converter comprising multiple DC-DC converter modules (30-1, 30-2). For this purpose, alongside the conventional controlling of the individual DC-DC converter modules, an additional correction variable (K-1, K-2) is determined which can be added to the control variable (R4-1, R4-2). In particular, the correction variable can take into account individual properties of the DC-DC converter modules, such as component tolerances or similar. For this purpose, correction values suitable for the individual DC-DC converter modules can be determined in advance and stored in a non-volatile storage means. Using these previously stored links, the control variables for the individual DC-DC converter modules can be individually adjusted.