Supercharge Your Innovation With Domain-Expert AI Agents!

PWM harmonic effective value calculation method

A calculation method and effective value technology, which is applied in the field of PWM harmonic effective value calculation, can solve problems such as complex process, difficulty in calculating the effective value of each harmonic, and calculating the effective value of each harmonic

Active Publication Date: 2020-02-07
苔花科迈西安信息技术有限公司
View PDF8 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The spectrum of this waveform often has main harmonics and more inter-harmonic waves, and the energy is distributed around each harmonic, so it is difficult to calculate the effective value of each harmonic
[0003] In the field of electromagnetic interference, the detector of the receiver has a certain bandwidth, and the energy within the bandwidth is received and the total effective value is detected, so the effective value of each harmonic is an important content in the interference calculation. Simple FFT transformation cannot directly obtain harmonic RMS
[0004] At present, the calculation steps for the effective value of each harmonic of PWM are as follows: After the PWM wave is transformed by FFT, since there are some inter-harmonic waves near the main peak of each harmonic, this makes the energy of each harmonic relatively scattered, not It is convenient to directly calculate the effective value of each harmonic
In order to calculate the total effective value near each harmonic, first use the bandpass filter to extract the spectrum energy near each harmonic, and then calculate the total effective value RMS, this process is complicated

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • PWM harmonic effective value calculation method
  • PWM harmonic effective value calculation method
  • PWM harmonic effective value calculation method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] A PWM harmonic effective value calculation method is characterized in that a sawtooth wave is constructed according to the PWM wave.

[0035] The PWM wave is the result of sawtooth wave carrier and sine wave modulation.

[0036] The PWM waves include unipolar PWM waves and bipolar PWM waves.

[0037] Described unipolar PWM wave causes the steps of sawtooth wave as follows:

[0038] A. Calculate the amplitude and frequency of the unipolar PWM wave;

[0039] B. Construct the sawtooth wave so that its frequency is the same as the carrier frequency of the unipolar PWM wave in A, and its amplitude is twice that of the unipolar PWM wave in A.

[0040] C. After the sawtooth wave is subjected to FFT operation, the peak value of each harmonic is obtained;

[0041] D. Divide the peak value of each harmonic by That is, the effective value of each harmonic of the unipolar PWM wave is obtained.

[0042] The slope of the sawtooth wave can be positive or negative, such as imag...

Embodiment 2

[0046] Described bipolar PWM wave causes the steps of sawtooth wave as follows:

[0047] A. Calculate the amplitude and frequency of the bipolar PWM wave;

[0048] B. Construct the sawtooth wave so that its frequency is the same as the carrier frequency of the bipolar PWM wave in A, and its amplitude is twice that of the bipolar PWM wave in A.

[0049] C. After the sawtooth wave is subjected to FFT operation, the peak value of each harmonic is obtained;

[0050] D. Divide the peak value of each harmonic by That is, the effective value of each harmonic of the bipolar PWM wave is obtained.

[0051] The slope of the sawtooth wave can be positive or negative, such as Figure 8 and Figure 9 shown.

[0052] Such as Figure 6 As shown, the bipolar PWM wave is modulated by a sawtooth wave carrier and a sine wave. After the bipolar PWM wave is transformed by FFT, the harmonic spectrum of each order is obtained as Figure 7 , the interharmonic wave near the main peak of each ha...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention belongs to the field of electromagnetic interference, and relates to a PWM harmonic effective value calculation method. According to the method, a PWM wave is constructed into a sawtoothwave, the frequency of the sawtooth wave is the same as the carrier frequency of the PWM wave, and the amplitude of the sawtooth wave is twice that of the PWM wave. By means of the method, the problem that the effective value of the PWM wave cannot be directly calculated can be effectively solved; after the PWM harmonic effective value calculation method is used, the effective value of each harmonic wave can be directly obtained in a subsequent simulation result, and in the field of electromagnetic compatibility simulation, the effective value result of each frequency point is visually obtained by utilizing the independence of each harmonic wave of the sawtooth wave.

Description

technical field [0001] The invention belongs to the field of electromagnetic interference, and in particular relates to a method for calculating effective values ​​of PWM harmonics. Background technique [0002] In the field of power electronics, PWM is a common control method. Its waveform is macroscopically periodic, and microscopically, the duty cycle is gradually changed. The frequency spectrum of this waveform often has main harmonics and more interharmonic waves, and the energy is distributed around each harmonic, so it is difficult to calculate the effective value of each harmonic. [0003] In the field of electromagnetic interference, the detector of the receiver has a certain bandwidth, and the energy within the bandwidth is received and the total effective value is detected, so the effective value of each harmonic is an important content in the interference calculation. A simple FFT transformation cannot directly obtain harmonic rms values. [0004] At present, t...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): G01R23/16
CPCG01R23/16
Inventor 符立梅董立红赵振民
Owner 苔花科迈西安信息技术有限公司
Features
  • R&D
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com