Multiphase Interleaving Converter Frequency Modulation for Harmonic Beats
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multiphase interleaving DC-DC converters face challenges in responding quickly to load transients due to high transient current rates, leading to increased costs and potential thermal unbalances, with existing control methods failing to effectively filter out harmful harmonics that cause beats in output voltage and current, affecting the converter's stability and reliability.
Innovation Solution
A frequency modulation method is introduced, where a modulated control voltage signal with reduced harmonic content at the switching frequency is generated and applied to the PWM modulator, using a suitable modulating frequency and modulation index to minimize harmonic generation, particularly at the switching frequency, and activated only during load transients to improve response speed and reduce beats.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the converter responds quickly to load transients to meet high transient current rates, then the response speed is improved, but harmful harmonics are generated causing beats in output voltage and current
Solution Approach 1:
The patent applies frequency modulation to the PWM control signal, intentionally introducing a modulating frequency component that shifts the harmful harmonics away from the dangerous beating frequencies. The modulation index is specifically chosen to minimize harmonic content at the switching frequency while maintaining fast transient response. This converts the harmful effect of harmonics into a beneficial frequency distribution that avoids resonance and beats.
Solution Approach 2:
The patent changes the frequency parameter of the control signal by applying frequency modulation with a specific modulating frequency and modulation index. This parameter change transforms the fixed-frequency PWM signal into a variable-frequency signal that dynamically adjusts the harmonic spectrum, preventing harmonics from settling at dangerous beating frequencies while maintaining the required response speed to load transients.
2Object-generated harmful factors
If frequency modulation is applied to reduce harmonics, then harmonic content at switching frequency is reduced, but control signal complexity increases
Solution Approach 1:
The patent replaces complex hardware filtering circuits with a software-based frequency modulation approach. Instead of adding physical filters to remove harmonics, the control system applies frequency modulation to the PWM signal, using mathematical relationships to shift and minimize harmonic content. This substitution reduces hardware complexity while achieving the same harmonic reduction effect.
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
This approach effectively reduces or eliminates beats at dangerous frequencies, enhancing the stability and reliability of the converter by minimizing harmonic energy in both voltage and current signals, even under high load frequency conditions, and improves the overall performance of the regulator.
Implementation Method 1
A frequency modulation method is introduced, where a modulated control voltage signal with reduced harmonic content at the switching frequency is generated and applied to the PWM modulator
Data Source
AI summary
An embodiment of method is described for controlling a voltage regulator of the type comprising at least one modulator of the PWM type, the method comprising:1) generation of a control voltage signal for said PWM modulator;2) frequency modulation of said control voltage signal obtaining a modulated control voltage signal having an harmonic at a switching frequency of said voltage regulator of reduced entity with respect to said control voltage signal; and3) application of said modulated control voltage signal to said PWM modulator for generating a driving signal for said voltage regulator.