Power Converter Phase Current Detection Using Inverted Voltage Vector Timing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power conversion apparatuses face challenges in accurately detecting phase currents due to the burden of detecting DC-side currents at multiple timings for different voltage vectors, leading to errors and increased processing complexity.
Innovation Solution
A power conversion apparatus with a switch controller that controls switching elements to output voltage vectors oppositely in the first and second half of a carrier period, and a phase current detector that alternates detection timing between first-half and latter-half timings to reduce the burden of phase current detection, using a timing switcher to select detection timing based on the output of the same kind of voltage vector.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If DC-side current is detected at multiple timings for different voltage vectors, then phase current detection accuracy is improved, but processing complexity and detection burden increase
Solution Approach 1:
The patent extracts only the necessary detection timing information from multiple voltage vector periods. Instead of processing all detected current values from multiple timings, the system selects and uses only those current values that correspond to identical voltage vectors, thereby reducing processing complexity while maintaining detection accuracy.
Solution Approach 2:
The patent inverts the conventional approach by not averaging all detected current values from multiple timings, but rather selecting current values that correspond to the same voltage vector condition. This inversion of the averaging logic reduces computational burden while preserving accuracy.
2Measurement precision
If DC-side current is detected at multiple timings, then phase current detection coverage is improved, but detection burden increases
Solution Approach 1:
The patent extracts only the essential detection data points that correspond to identical voltage vectors from the multiple detection timings. By taking out only the relevant current values and discarding redundant ones, the system maintains comprehensive detection coverage while significantly reducing the detection burden.
3Device complexity
If detection timing is fixed, then processing simplicity is improved, but detection accuracy deteriorates due to errors
Solution Approach 1:
The patent implements dynamic detection timing selection based on the actual voltage vector output sequence. The detection timing is not fixed but adapts to match the voltage vector pattern, allowing the system to maintain processing simplicity while improving detection accuracy by selecting optimal timing points.
Solution Approach 2:
The patent changes the detection timing parameter dynamically to correspond with the voltage vector output timing. By adjusting the detection timing parameter to match when identical voltage vectors are output, the system achieves both processing simplicity and high detection accuracy.
Data Source
AI summary
A power conversion apparatus includes: a power converter that includes a plurality of switching elements; a switch controller that controls the plurality of switching elements so that the order of outputting a plurality of kinds of voltage vectors from the power converter is opposite in a first half and a latter half of a carrier period; a DC-side current detector that detects a DC-side current of the power converter; and a phase current detector that detects one phase current among three phase currents on the basis of the detected DC-side current at a detection timing, the detection timing being selected from a first-half timing and a latter-half timing of the carrier period at which the same kind of voltage vector is output. The phase current detector includes a timing switcher that alternately switches the detection timing between the first-half timing and the latter-half timing.