Interleaved Converter Current Equalization Using Dual-Mode Control
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Solution Overview
Problem
Existing power conversion technologies fail to adequately equalize reactor currents across phases due to piece-to-piece variations in reactor inductance values, which can occur during production or due to aging, leading to inefficient operation.
Innovation Solution
A power conversion apparatus with a converter circuit comprising unit converters and detectors for current and voltage, along with controllers that adjust operation based on detected values to equalize reactor currents, using a low current-oriented controller when currents are low and a high current-oriented controller when currents are high, to account for variations in reactor inductance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional balance control technology is used, then the system operates with standard control methods, but reactor currents cannot be sufficiently equalized when piece-to-piece variation occurs among reactors
Solution Approach 1:
The control system dynamically switches between two control modes (first control when detection value ≤ first threshold, second control when detection value > first threshold) based on real-time reactor current detection. This dynamic adaptation allows the system to handle piece-to-piece variation among reactors effectively, improving current equalization capability while maintaining reliability.
Solution Approach 2:
The system changes control parameters (detection thresholds and control strategies) based on the detected reactor current values. By comparing detection values with thresholds and adjusting control modes accordingly, the system adapts to reactor variations and maintains effective current equalization across different operating conditions.
2Measurement precision
If multiple current detectors are used to monitor each reactor, then precise individual current detection is achieved, but device complexity increases
Solution Approach 1:
The patent merges the function of multiple individual current detectors into a single current detector that measures the sum of currents flowing through all reactors. This single detector provides sufficient information for balance control by detecting total current, thereby reducing device complexity while maintaining the capability to equalize reactor currents through appropriate control strategies.
Solution Approach 2:
The single current detector serves multiple functions: it detects the sum of reactor currents, provides feedback for balance control, and enables the system to adapt to reactor variations. This multi-functional approach eliminates the need for multiple dedicated detectors, simplifying the overall system while preserving measurement and control capabilities.
Data Source
AI summary
A power conversion apparatus includes a converter circuit converting AC voltage output from an AC power supply into DC voltage. The converter circuit includes unit converters. The power conversion apparatus includes a low current-oriented controller the unit converters to cause current corresponding to a single phase to flow through a current detector, and a high current-oriented controller controlling operation of the unit converters based on a result of comparison between a duty command and a carrier signal, where the duty command is generated based on detection values detected by the current detector and a voltage detector. When the detection value detected by the current detector is less than or equal to a first threshold, the low current-oriented controller is activated, and when the detection value detected by the current detector is greater than the first threshold, the high current-oriented controller is activated.