System and method for metering and analyzing electric energy as well as analog-to-digital conversion circuit

An analog-to-digital conversion circuit and energy metering technology, applied in the field of smart grid, can solve the problems of unsatisfactory real-time synchronization effect, high product cost, and large structural complexity, and achieve good actual test results, less hardware cost, and improved stability. Effect

CN102035554AActive Publication Date: 2011-04-27HI TREND TECH SHANGHAI
2 Cites 18 Cited by

Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2011-04-27

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention discloses a system and a method for metering and analyzing electric energy as well as an analog-to-digital conversion circuit, belonging to the field of intelligent grid. In the invention, two sampling units are simultaneously connected behind a sigma-delta modulation unit, wherein the D value of the first sampling unit is fixed for metering the electric energy and the D value of the second sampling unit is variable for analyzing sub-harmonic waves so as to improve the monitoring stability of the sub-harmonic waves and ensure the accuracy for metering the electric energy in the cost of less hardware. During variation of the grid frequency, the D value of the second sampling unit is automatically calculated and adjusted to realize self-adaptive adjustment and maintain the monitoring stability of sub-harmonic waves. Coefficient compensation is performed on the harmonic component in the second sampling unit so as to avoid attenuation of a transition zone of a medium-high frequency part resulting from using a 3-order CIC (Cascaded Integrator Comb) filter.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention relates to the field of smart grids, in particular to electric energy measurement and sub-harmonic analysis technology in smart grids. Background technique

[0002] In recent years, with the vigorous development of the smart grid, people are paying more and more attention to the quality of the real-time operation of the grid, and the call for subharmonic analysis is also getting higher and higher.

[0003] The sub-harmonic referred to in the present invention is a kind of harmonic, and its frequency is N of the fundamental frequency, and N is an integer.

[0004] At present, most schemes for subharmonic analysis choose the mainstream Fourier spectrum analysis, but in practical applications, there is a difficult problem that the sampling rate cannot be synchronized with the grid frequency.

[0005] The operating frequency of China's power grid is 50Hz. However, the frequency of the power grid in actual operation usually fluctuates around ...

Examples

Embodiment Construction

[0037] In the following description, many technical details are proposed in order to enable readers to better understand the application. However, those skilled in the art can understand that without these technical details and various changes and modifications based on the following implementation modes, the technical solution claimed in each claim of the present application can be realized.

[0038] In order to make the object, technical solution and advantages of the present invention clearer, the implementation manner of the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0039] The first embodiment of the present invention relates to an analog-to-digital conversion circuit. figure 1 It is a schematic diagram of the structure of the analog-to-digital conversion circuit. The analog-to-digital conversion circuit includes:

[0040] The Σ-Δ modulation unit is used for performing single-bit sampling on the input ana...