Auxiliary Voltage Balancing in Parallel DC/DC Converters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrical DC/DC converters, when operated in parallel without closed-loop control, experience unequal current distribution leading to overloading and reduced output power due to passive current distribution influenced by electric and thermal losses and parasitic elements.
Innovation Solution
A method and controller that utilize auxiliary voltage sources electrically coupled in series with each converter to adjust compensation voltages, ensuring equal current distribution by generating compensation signals based on current differences, thereby preventing overloading and enhancing output power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If several electrical converters are operated in parallel without closed-loop control, then the device complexity is reduced, but the current distribution becomes unequal leading to overloading and reduced output power
Solution Approach 1:
The patent implements a feedback mechanism where current values from each parallel converter are monitored and fed back to a control unit. The control unit calculates current differences and generates compensation signals based on this feedback to actively balance the current distribution among converters, resolving the contradiction between simple operation and equal load sharing.
Solution Approach 2:
The patent changes the operating parameters of individual converters by adding compensation voltages to their input or output. This parameter adjustment allows each converter to operate at its optimal point while maintaining equal current distribution, thereby increasing total output power without requiring complex control architecture.
2Productivity
If several electrical converters are operated in parallel without current balancing, then the available output current increases, but some converters become overloaded while others are underutilized
Solution Approach 1:
The control unit continuously monitors current values from each converter and uses this feedback information to generate appropriate compensation signals. This ensures that each converter operates within its rated capacity while contributing equally to the total output current, maintaining both high productivity and reliability.
Solution Approach 2:
The patent introduces auxiliary voltage sources as intermediary elements between the main power stage and the load. These intermediaries provide the necessary compensation voltages to balance current distribution, allowing the parallel converters to share the load equally without direct complex interaction between them.
3Productivity
If compensation voltages are added to balance current distribution, then equal load sharing is achieved, but the device complexity increases due to auxiliary voltage sources
Solution Approach 1:
The control unit serves multiple functions: it monitors current values from all converters, calculates current differences, determines compensation voltage values, and generates control signals for the auxiliary voltage sources. This multi-functionality reduces the need for separate dedicated components for each function, thereby limiting the increase in device complexity.
Solution Approach 2:
The patent merges the control of multiple parallel converters into a single integrated control unit that processes information from all converters and coordinates their operation. This consolidation approach achieves equal load sharing while minimizing the number of independent control circuits and auxiliary components required.
Data Source
AI summary
A converter arrangement is configured for converting a first DC bus voltage into a second DC bus voltage and comprises a first and second electrical converters, and a first auxiliary voltage source. A method of operation comprises receiving a first current value and receiving a second current. The method further comprises determining a difference between the first and second current values. The method additionally comprises determining a first compensation voltage value based on the difference such that the first and second currents correspond when the first compensation voltage is added to the first DC bus voltage or when the first compensation voltage is added to a first output voltage. The method also comprises sending a first compensation signal to the first auxiliary voltage source. The first auxiliary voltage source is configured to add the first compensation voltage to the first DC bus voltage or to the first output voltage.