Three-Phase DC-DC Converter Frequency Control for Load-Dependent Losses
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Three-phase DC-DC converters face inefficiencies due to thermal management challenges and power loss variations with load fluctuations, as conventional control methods are optimized for a single PWM frequency, leading to suboptimal performance across varying output power ranges.
Innovation Solution
A system comprising a three-phase primary converter coupled to a secondary converter via a transformer, with a controller that adjusts modulation frequency and variable inductance to maintain optimal operation points based on load curves, minimizing thermal energy dissipation and power losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional control methods with fixed PWM frequency are used, then the converter operates stably at a single frequency, but power loss increases and thermal management becomes challenging when load conditions vary
Solution Approach 1:
The patent implements dynamic modulation frequency adjustment based on load conditions. The controller selects from multiple PWM frequencies (e.g., 5kHz, 10kHz, 15kHz, 20kHz, 25kHz, 30kHz, 35kHz, 40kHz, 45kHz, 50kHz) depending on the output power range, transforming the fixed-frequency system into an adaptive dynamic system that optimizes efficiency across varying loads
Solution Approach 2:
The patent changes the modulation frequency parameter according to load conditions. By dividing the output power range into multiple ranges and assigning different optimal frequencies to each range, the system adjusts key operational parameters to minimize power loss at different operating points
2Temperature
If single PWM frequency control is used, then the control system remains simple, but thermal management performance deteriorates across varying output power ranges
Solution Approach 1:
The controller dynamically adjusts modulation frequency based on detected output power levels, selecting from multiple predefined frequencies to optimize thermal performance across different operating conditions without requiring complex real-time optimization algorithms
Solution Approach 2:
The system uses feedback from the detected output power range to select the appropriate modulation frequency. The controller continuously monitors load conditions and adjusts the PWM frequency accordingly, creating a closed-loop control system that optimizes thermal management
3Productivity
If fixed frequency operation is maintained, then the converter design remains straightforward, but efficiency decreases when operating outside the optimal frequency point
Solution Approach 1:
The system transitions from static fixed-frequency operation to dynamic multi-frequency operation, where the modulation frequency changes based on the output power range to maintain optimal conversion efficiency across the entire operating spectrum
Solution Approach 2:
The patent implements parameter change by adjusting the modulation frequency according to load conditions. Different frequency ranges are assigned to different output power ranges, allowing the system to operate at optimal efficiency points regardless of load variations
Data Source
AI summary
At least one example embodiment provides a system comprising a three-phase direct-current-to-direct-current converter (DC-DC converter) including a three-phase primary converter coupled to a three-phase secondary converter via at least one transformer; and a controller configured to cause the system to, obtain a load curve based on an operational load ratio or percentage of the three-phase DC-DC converter, the load curve associated with at least one phase of the primary converter and the secondary converter, and adjust or maintain a modulation frequency of the at least one phase of the primary converter and the secondary converter consistent with an operation point on the obtained load curve.