Converter Device Phase-Shifted Control for Harmonic Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional converter devices require multiple components for current and voltage detection, leading to increased size and complexity, which complicates the decision to operate the extension switching circuit, making them bulky and costly.
Innovation Solution
A converter device with two switching circuits and a control system that uses inductive elements and switching means to generate phase-deviated switching signals, allowing for open-loop control without precise sensors, reducing switching frequency and harmonic distortion, and incorporating SiC diodes to minimize reverse recovery current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple components (current detector, voltage detector, control signal switch) are added to determine extension switching circuit operation, then the control precision is improved, but the device size increases
Solution Approach 1:
The patent combines the current detection and voltage detection functions into the control means itself, eliminating the need for separate detector components. The control means directly determines extension switching circuit operation based on system state, merging multiple detection and control functions into a single integrated unit, thereby improving control precision without increasing device size.
Solution Approach 2:
The control means is designed to perform multiple functions: it controls the basic switching circuit, determines the operation state of the extension switching circuit, and integrates both current and voltage detection capabilities. This multi-functional design eliminates the need for separate specialized components, reducing overall device size while maintaining precise control.
2Measurement precision
If multiple components and complex control structure are used, then the control accuracy is improved, but the device complexity increases
Solution Approach 1:
The patent merges the control signal generation for the basic switching circuit and the extension switching circuit into a single control means. By integrating these control functions, the patent reduces device complexity while maintaining accurate control through unified management of switching operations.
Solution Approach 2:
The control means autonomously determines when to operate the extension switching circuit based on system conditions, eliminating the need for separate control signal switches and complex external control logic. This self-service approach simplifies the overall device structure while preserving control accuracy.
3Productivity
If high switching frequency is used, then the power conversion efficiency is improved, but the switching loss increases
Solution Approach 1:
The patent employs periodic switching control where the extension switching circuit is operated only during specific periods when system conditions require it. This periodic operation allows the system to achieve efficient power conversion during active periods while minimizing switching losses during inactive periods, balancing efficiency and energy loss.
Solution Approach 2:
The patent dynamically adjusts the switching frequency and operation mode of the extension switching circuit based on real-time system conditions. By making the switching behavior adaptive rather than fixed, the system optimizes power conversion efficiency while minimizing switching losses under varying operating conditions.
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 results in a downsized, simplified converter device with reduced switching loss, cost, and harmonic distortion, enabling efficient DC power conversion while maintaining regulatory compliance for noise and harmonic regulations.
Implementation Method 1
an inductive element that is serially provided in a positive electrode bus line which connects the rectification means and the smoothing means
Implementation Method 2
incorporating SiC diodes to minimize reverse recovery current
Data Source
Figure 1
Figure 2
Figure 3(a)~3(d)
AI summary
A converter device (2) has two switching circuits (10a, 10b) provided in parallel with each other in between a rectifier circuit (5) and a smoothing capacitors (12). A converter control unit (15) compares a reference waveform of a predetermined carrier frequency with a voltage command so as to generate a first switching signal for one switching circuit, and compares an inverted reference waveform having a phase deviated by 180 degrees from the phase of the reference waveform, with the voltage command so as to generate a second switching signal for the other switching circuit. By controlling opening and closing of the switching elements (8a, 8b) in the switching circuits (10a, 10b) based on the first switching signal and the second switching signal, DC voltage is increased and a harmonic of an AC-side input current is reduced, as a result of which downsizing and simplification of the device are achieved.