Power Converter Phase Control for Reactor Current Balancing
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Solution Overview
Problem
The existing power conversion technologies, such as those described in Patent Literature 1, suffer from reduced efficiency due to current balance control methods that do not consider the magnitude of reactor currents, leading to inefficiencies in converter performance.
Innovation Solution
A power conversion apparatus with a converter circuit comprising multiple unit converters and current detectors, where the phase difference between adjacent unit converters is adjusted based on the total or average current detected, allowing for more efficient current balancing by modifying the switching element activation times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If current balance control is performed regardless of reactor current magnitude, then reactor currents are equalized, but converter efficiency is reduced
Solution Approach 1:
The patent changes the control parameter from fixed phase difference to variable phase difference based on current magnitude. When current exceeds a threshold, the phase difference between adjacent unit converters is adjusted from the reference value, enabling adaptive current balancing that minimizes efficiency loss while maintaining current equality.
Solution Approach 2:
The patent introduces dynamic adjustment of switching phases based on real-time current detection. The phase difference between unit converters is made variable rather than fixed, allowing the system to adapt its operation mode according to load conditions and current magnitude, thereby optimizing both current balance and efficiency.
2Stability of the object's composition
If phase difference is changed to equalize reactor currents, then current distribution is improved, but switching complexity increases
Solution Approach 1:
The patent implements a feedback mechanism where current detectors monitor reactor currents and feed this information to the control device. Based on the detected current magnitude, the control device automatically adjusts the phase difference between unit converters, creating a closed-loop control system that simplifies the overall control strategy while achieving current equalization.
Solution Approach 2:
The system uses its own current detection capability to automatically adjust its switching phases. The control device leverages the existing current detection infrastructure to self-regulate the phase difference, eliminating the need for external control inputs or complex predetermined scheduling.
Data Source
AI summary
The power conversion apparatus includes a converter circuit that converts an alternating-current voltage output from an alternating-current power supply into a direct-current voltage. The converter circuit includes unit converters. The power conversion apparatus includes current detectors that detect respective currents flowing through respective reactors. In first and second unit converters adjacent to each other among the unit converters, a phase difference between a first phase and a second phase is changed from a reference phase difference when a total current of currents detected by the respective current detectors is greater than a threshold. The first phase is a phase at a time when the switching element of the first unit converter is turned on. The second phase is a phase at a time when the switching element of the second unit converter is turned on.