Interleaved Converter PWM for Single-Sensor Reactor Current Leveling
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Solution Overview
Problem
Existing power converting apparatuses require individual current detectors for each phase, leading to increased manufacturing costs and complexity.
Innovation Solution
A power converting apparatus with a converter circuit that includes unit converters for multiple phases, each with a reactor and switching elements, utilizing a single current detector to measure the sum of currents through reactors and a control device to generate pulse-width modulation signals based on detected values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If individual current detectors are used for each phase to perform current balancing control, then reactor current leveling is achieved, but manufacturing cost increases
Solution Approach 1:
The patent merges the current detection function from multiple individual detectors into a single current detector that measures the sum of currents flowing through all reactors. This combining approach maintains the ability to perform current balancing control while reducing the number of detectors needed, thereby lowering manufacturing cost.
Solution Approach 2:
The patent introduces a computational intermediary (the control device) that calculates individual reactor currents by subtracting measured sum currents from reference currents. This intermediary computation allows the system to derive individual phase information from a single sum measurement, eliminating the need for multiple physical detectors.
2Measurement precision
If individual current detectors are used for each phase, then accurate current detection is achieved, but device complexity increases
Solution Approach 1:
The patent combines multiple current detection functions into a single current detector, reducing device complexity while maintaining measurement precision through computational processing of the sum current signal.
Solution Approach 2:
The patent replaces physical mechanical detectors (multiple current detectors) with a computational system that calculates individual currents from sum current measurements, substituting hardware complexity with software processing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution allows for leveling of reactor currents while preventing an increase in manufacturing cost, by using a single current detector and optimizing the switching pattern to reduce current ripple imbalances.
Implementation Method 1
a control device generating a reference duty on the basis of detection values of the current detector and the voltage detector and generating, on the basis of a result of comparison between the reference duty and a carrier signal, a pulse-width modulation signal for controlling the switching element
Implementation Method 2
each of the unit converters including one reactor and at least one switching element
Data Source
AI summary
A power converting apparatus includes a converter circuit converting an alternating-current voltage output from an alternating-current power supply into a direct-current voltage. The converter circuit includes unit converters. The power converting apparatus generates a reference duty on the basis of detection values of a current detector and a voltage detector and generates, on the basis of a result of comparison between the reference duty and a carrier signal, a pulse-width modulation signal for controlling the switching element. In each of the unit converters, the pulse-width modulation signal has one pulse within a carrier period and has pulses for the number of phases within a leveling period, the leveling period being obtained by multiplying the carrier period by the number of phases. The pulses for the number of phases within the leveling period have phases all different from each other in the respective carrier periods.