CN208921784U - Frequency detecting device - Google Patents
Frequency detecting device Download PDFInfo
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- CN208921784U CN208921784U CN201821490821.8U CN201821490821U CN208921784U CN 208921784 U CN208921784 U CN 208921784U CN 201821490821 U CN201821490821 U CN 201821490821U CN 208921784 U CN208921784 U CN 208921784U
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Abstract
The utility model provides a kind of frequency detecting device, comprising: filter unit interconnected and frequency detecting unit；Wherein the filter unit includes: the first filtering unit, and the output end of first filtering unit is connect with the input terminal of the frequency detecting unit；The output end of second filtering unit, second filtering unit is connect with the input terminal of the frequency detecting unit.First filtering unit is low-pass first order filter.First filtering unit is multiple cascade low-pass first order filters.Second filtering unit is low-pass first order filter.Second filtering unit is multiple cascade low-pass first order filters.Compared with prior art, the utility model frequency detecting device has the advantage that Digital Realization calculation amount is small, has very high detection accuracy, while being suitable for single-phase and three-phase system.
Description
Technical field
The utility model relates to a kind of frequency detecting devices.
Background technique
Frequency is an important electric parameter, is important evidence in power electronic equipment design, as inductor design,
Harmonics Calculation etc..So in many systems, the accurate frequency for measuring voltage is essential work.Common measurement and
The method for calculating frequency has: 1) time interval between two adjacent zero crossings of measurement voltage signal, inverse is exactly its frequency, but
It is that often will appear multiple zero crossings when voltage has harmonic components to cause erroneous detection or detection inaccurate；2) vector method: i.e. certain
The angle of Vector Rotation in time interval can also calculate frequency, but vector method is only applicable to three-phase system, and three-phase is not
Balance and its detection accuracy of voltage harmonic still extreme influence.
Utility model content
For the defects in the prior art, the utility model aim is to provide a kind of frequency of simple and quick detection frequency of energy
Rate detection device.
In order to solve the above technical problems, the utility model provides a kind of frequency detecting device, comprising: filtering interconnected
Unit and frequency detecting unit；Wherein the filter unit includes: the first filtering unit, the output end of first filtering unit
It is connect with the input terminal of the frequency detecting unit；Second filtering unit, the output end and the frequency of second filtering unit
The input terminal of rate detection unit connects.
Preferably, first filtering unit is low-pass first order filter.
Preferably, first filtering unit is multiple cascade low-pass first order filters.
Preferably, second filtering unit is low-pass first order filter.
Preferably, second filtering unit is multiple cascade low-pass first order filters.
A kind of frequency detecting device, including filter unit interconnected and frequency detecting unit；Wherein
The filter unit includes:
The output end of first filtering unit, first filtering unit is connect with the input terminal of the frequency detecting unit；
The output end of second filtering unit, second filtering unit is connect with the input terminal of the frequency detecting unit；
First filtering unit is low-pass first order filter；
First filtering unit is multiple cascade low-pass first order filters；
Second filtering unit is low-pass first order filter；
Second filtering unit is multiple cascade low-pass first order filters.
Compared with prior art, the utility model frequency detecting device has the advantage that Digital Realization calculation amount is small,
With very high detection accuracy, while being suitable for single-phase and three-phase system.
Detailed description of the invention
Upon reading the detailed description of non-limiting embodiments with reference to the following drawings, other spies of the utility model
Sign objects and advantages will become more apparent upon.
Fig. 1 is the utility model frequency detecting device functional block diagram；
Fig. 2 is the utility model frequency detecting device filter unit functional block diagram.
In figure:
1- frequency detecting unit 2- filter unit the first filtering unit of 3-
4- the second filtering unit 5- low-pass first order filter
Specific embodiment
The utility model is described in detail combined with specific embodiments below.Following embodiment will be helpful to this field
Technical staff further understands the utility model, but does not limit the utility model in any form.It should be pointed out that ability
For the those of ordinary skill in domain, without departing from the concept of the premise utility, several changes and improvements can also be made.
As shown in Figure 1, the utility model increases filter unit 2 before frequency detecting unit 1, input voltage letter is filtered out
Then harmonic components in number Vin use the frequency detecting method based on zero crossing, the accurate frequency for obtaining signal.
Required digital filter needs to filter out all harmonic components in addition to fundamental wave, including direct current well.This
In use filter unit 2 as shown in Figure 2.Wherein the first filtering unit 3 and the second filtering unit 4 are all by first-order low-pass wave
Device 5 forms, and is easy Digital Realization, and for the system of power frequency 50Hz, the cutoff frequency of the first filtering unit 3 is designed in 75Hz,
The cutoff frequency design of second filtering unit 4 is in 25Hz, so the first filtering unit 3 is for filtering out high fdrequency component, the second filtering
Component 4 finally obtains fundametal compoment Vinf for obtaining DC component.Two low-pass filter cascades can greatly promote filtering
Effect.
Specific embodiment of the utility model is described above.It is to be appreciated that the utility model not office
It is limited to above-mentioned particular implementation, those skilled in the art can make a variety of changes or modify within the scope of the claims,
This has no effect on the substantive content of the utility model.In the absence of conflict, the spy in embodiments herein and embodiment
Sign can be arbitrarily combined with each other.
Claims (6)
1. a kind of frequency detecting device, which is characterized in that including filter unit interconnected and frequency detecting unit；Wherein
The filter unit includes:
The output end of first filtering unit, first filtering unit is connect with the input terminal of the frequency detecting unit；
The output end of second filtering unit, second filtering unit is connect with the input terminal of the frequency detecting unit.
2. frequency detecting device according to claim 1, which is characterized in that first filtering unit is first-order low-pass
Wave device.
3. frequency detecting device according to claim 1, which is characterized in that first filtering unit is multiple cascade
Low-pass first order filter.
4. frequency detecting device according to claim 1, which is characterized in that second filtering unit is first-order low-pass
Wave device.
5. frequency detecting device according to claim 1, which is characterized in that second filtering unit is multiple cascade
Low-pass first order filter.
6. a kind of frequency detecting device, which is characterized in that including filter unit interconnected and frequency detecting unit；Wherein
The filter unit includes:
The output end of first filtering unit, first filtering unit is connect with the input terminal of the frequency detecting unit；
The output end of second filtering unit, second filtering unit is connect with the input terminal of the frequency detecting unit；
First filtering unit is low-pass first order filter；
First filtering unit is multiple cascade low-pass first order filters；
Second filtering unit is low-pass first order filter；
Second filtering unit is multiple cascade low-pass first order filters.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821490821.8U CN208921784U (en) | 2018-09-12 | 2018-09-12 | Frequency detecting device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821490821.8U CN208921784U (en) | 2018-09-12 | 2018-09-12 | Frequency detecting device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN208921784U true CN208921784U (en) | 2019-05-31 |
Family
ID=66705316
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201821490821.8U Active CN208921784U (en) | 2018-09-12 | 2018-09-12 | Frequency detecting device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN208921784U (en) |
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2018
- 2018-09-12 CN CN201821490821.8U patent/CN208921784U/en active Active
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