An effective value measurement method and system based on digital filtering
A technology of digital filtering and measurement method, applied in the direction of RMS measurement, etc., can solve the problems of difficulty in applying the real-time and accuracy requirements of RMS data, long time for filtering to achieve stability, and high requirements for DC filter performance, and achieve low ripple. , the effect of short filter delay and small intensity requirements
Inactive Publication Date: 2015-08-12
常州昊云工控科技有限公司
View PDF6 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
When this existing method measures the rms value of a pure sinusoidal or AC signal with fewer harmonics, the intermediate signal r 2 ( n ) has large ripples, so the performance requirements for DC filtering are high, and the filtering takes a long time to reach stability.
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 moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0054] The principle block diagram of the embodiment of the present invention is as image 3 As shown, its system structure is as follows Figure 4 shown. refer to image 3 with Figure 4 , the working process of the present invention based on digital phase-shift filtering effective value measurement embodiment is as follows.
[0055] Step 1: First, the analog electrical signal measured from the 50Hz power frequency grid r ( t ) according to the fixed sampling frequency F s =2000Hz for analog-to-digital conversion to obtain discrete digital electrical signals r ( n ). The frequency range of the AC signal is (40, 960) Hz, that is f 1 =40Hz, f 2 =960Hz. Sampling frequency F s Satisfy F s >2× f 2 .
[0056] Step 2: The digital electrical signal obtained in the above step 1 r ( n ) pass through two sets of digital phase-shift filters at the same time ( F 1) and ( F 2) After that, the phase-shifted signals are obtained respectively r x ( n ) and phase-sh...
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
Login to View More Abstract
The invention relates to an effective value measuring method and system based on digital filtering, and belongs to the field of electrical parameter measuring technology. The method is characterized by the following steps: firstly, converting an inputted AC electric signal into a digital electrical signal through an analog-digital converter; then, processing the digital electrical signal through two digital phase-shift filters to obtain a pair of phase-shift signals; and at last, performing arithmetic operation, DC filtering and root-extracting on the pair of phase-shift signals and effective value data is measured. The system is characterized in that: the system is composed of the analog-digital converter, a pair of digital phase-shift filters, a pair of multiplier, an adder, an operational amplifier, a DC filter and a root extractor. With the method and the system, a digitalized measurement of the effective value is realized; with the method, the ripple of an intermediate signal is small; performance requirement of the DC filter is low; measuring speed is fast; and requirements that control equipment, on the fields such as power electronics control, relay protection and the like, is high in timeliness and accuracy for the effective value measuring results are met.
Description
technical field [0001] The invention relates to an effective value measurement method and system based on digital filtering, and belongs to the technical field of electrical parameter measurement. Background technique [0002] Effective value is a basic AC parameter, which is widely used in electrical measurement, power monitoring and other occasions. Fast and accurate measurement of effective values has always been an important research topic in the field of electrical measurement. [0003] According to electrotechnical theory, the period is T AC signal r ( t ) effective value R for [0004] . [0005] The principle of the digital effective value measurement method widely used at present is as follows: figure 1 shown. This method is to input alternating current signals such as voltage and current r ( t ), after analog-to-digital conversion, the sampled digital electrical signal is obtained r ( n ), realized by the squarer r ( n )with r ( n ), and get r ...
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
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): G01R19/02
Inventor 庞浩
Owner 常州昊云工控科技有限公司