Method for extracting double-frequency alternating-current component under rotating coordinate system

A technology of rotating coordinate system and AC component, which is applied in measuring devices, measuring electrical variables, measuring current/voltage, etc., can solve the problem of slow extraction speed of voltage positive sequence components, achieve high-performance signal detection and power equipment control, and realize The effect of simple process and good application value

Inactive Publication Date: 2020-08-11
ELECTRIC POWER RES INST STATE GRID SHANXI ELECTRIC POWER
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  • Abstract
  • Description
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Problems solved by technology

[0003] Aiming at the disadvantage of slow extraction speed of voltage positive sequence components under existing unbalanced working conditions, the present invention provides a method for extracting double frequency AC components in a rotating coordinate system

Method used

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  • Method for extracting double-frequency alternating-current component under rotating coordinate system
  • Method for extracting double-frequency alternating-current component under rotating coordinate system
  • Method for extracting double-frequency alternating-current component under rotating coordinate system

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Embodiment

[0076] Such as Figure 1-11 As shown in the present invention, a method for extracting double-frequency AC components under a rotating coordinate system, a method for extracting double-frequency AC components under a rotating coordinate system, including: a power grid voltage signal acquisition module, and a synchronous rotating coordinate transformation module , Delayed sampling period filter module, amplitude and phase calculation module, synchronous rotation coordinate inverse transformation module. Include the following steps:

[0077] (1) The grid voltage signal acquisition module collects the three-phase unbalanced voltage signal of the grid voltage, and obtains the three-phase grid voltage signal including positive sequence and negative sequence components. The unbalanced three-phase grid voltage signal is composed of positive sequence components and negative sequence components, and the three-phase voltage can be expressed by the following formula:

[0078] U=U + + ...

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Abstract

The invention belongs to the field of power electronics, and particularly discloses a method for extracting a double-frequency alternating-current component under a rotating coordinate system, which comprises a power grid voltage signal acquisition module, a synchronous rotating coordinate transformation module, a delay sampling period filtering module, an amplitude and phase calculation module and a synchronous rotating coordinate inverse transformation module. Only the asymmetric three-phase voltage needs to be subjected to synchronous rotation coordinate transformation, and then a direct-current component, namely a positive-sequence component, under a synchronous rotation coordinate system can be accurately obtained by utilizing a delay sampling periodic filtering algorithm. And the delay sampling periodic filtering module is used for quickly separating the positive sequence voltage component from the negative sequence voltage component by delaying the voltage component on the synchronous rotating coordinate system for two sampling periods.

Description

technical field [0001] The invention relates to the field of power electronics, in particular to a practical method for quickly and accurately extracting double-frequency AC components in a rotating coordinate system, which is suitable for unbalanced power grid conditions. Background technique [0002] Unbalanced grid voltage faults will have a great impact on the stable operation of the grid-connected inverter system. Quickly and accurately obtaining the positive sequence component of the grid voltage is a key issue for the normal operation of the grid-connected power electronic system and the realization of high-performance control, phase detection, frequency detection, etc. Under the condition of three-phase unbalanced grid voltage, fast and accurate acquisition of the positive sequence components of voltage and current is the basic requirement to ensure the normal operation of grid-connected inverters. The three-phase unbalanced voltage appears as a DC component and a d...

Claims

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Application Information

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IPC IPC(8): G01R19/00
CPCG01R19/00
Inventor 曲莹郑惠萍李明贤唐震郝捷刘新元张一帆张谦暴悦爽高宏皮军
Owner ELECTRIC POWER RES INST STATE GRID SHANXI ELECTRIC POWER
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