Power Control Apparatus Reducing Harmonic Noise via Frequency Modulation
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Solution Overview
Problem
Existing power conversion apparatuses experience harmonic noise due to constant carrier wave frequency, which affects the performance of both the apparatuses and peripheral electronic devices, and while modulating the carrier wave frequency can reduce this noise, it introduces noise from the modulation frequency.
Innovation Solution
A power control apparatus and method that further modulates the carrier wave frequency with a variable modulation frequency, increasing the bandwidth of harmonic noise caused by the modulation frequency to reduce its impact, thereby minimizing both types of noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the carrier wave frequency is kept constant, then the power conversion apparatus operates stably, but harmonic noise occurs and adversely affects apparatuses and peripheral electronic devices
Solution Approach 1:
The patent applies dynamics by making the carrier wave frequency variable instead of constant. The frequency modulation unit varies the carrier wave frequency over time according to a predetermined pattern, transforming the static frequency into a dynamic one. This resolves the contradiction by maintaining operational stability through controlled variation rather than fixed frequency, thereby reducing harmonic noise while preserving system stability.
Solution Approach 2:
The patent changes the frequency parameter of the carrier wave from a constant value to a time-varying value. By modulating the frequency parameter according to a predetermined pattern, the system reduces harmonic noise generation while maintaining stable operation. This parameter change approach directly addresses the contradiction between frequency stability and noise reduction.
Data Source
AI summary
A power control apparatus and power control method that reduce harmonic noise produced when modulating a carrier wave frequency over predetermined cycles. A command value signal is generated for obtaining a desired output voltage, and a carrier wave is output. The frequency of the carrier wave is modulated by a desired frequency over predetermined cycles, and the desired frequency also modulates. The carrier wave is compared to a command value signal and a resulting control signal is provided to a switching unit. Harmonic noise caused by the modulation frequency can be spread, and the peak of the harmonic noise caused by the first modulation frequency can be reduced. Therefore, noise caused by a modulation frequency can be reduced.