Three-phase alternating current voltage drop state judgment method and system

A voltage sag, three-phase AC technology, applied in the direction of measuring current/voltage, measuring electrical variables, measuring devices, etc., can solve the problems of oscillation, irregular current and voltage, etc.

Inactive Publication Date: 2017-08-22
CHINA ELECTRIC POWER RES INST +2
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] At present, the energy storage and energy conversion unit PCS (power conversion system) all use DSP controllers. When the voltage drop is deep, irregular current and voltage oscillations will o

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  • Three-phase alternating current voltage drop state judgment method and system
  • Three-phase alternating current voltage drop state judgment method and system
  • Three-phase alternating current voltage drop state judgment method and system

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Embodiment Construction

[0058] The technical solution of the present invention will be described in further detail below in conjunction with the accompanying drawings.

[0059] The energy storage and energy conversion unit PCS uses a DSP chip as the main controller, and its judgment on the state of the grid voltage drop is realized through the flag bit. When the PCS is working normally, the grid voltage drop flag is detected = 0; when the PCS detects that a voltage drop occurs, the grid voltage drop flag = 1.

[0060] First, the three-phase voltage obtained after sampling is transformed by 3s / 2r, that is, from the three-phase stationary coordinate system to the two-phase rotating coordinate system and the separation of positive and negative sequence voltage components. At this time, the positive and negative sequence components are the voltage component values, And without filtering, u can be obtained after filtering dflt and u qflt Determine whether the grid voltage drops.

[0061] Since the nega...

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Abstract

The invention provides a three-phase alternating current voltage drop state judgment method and system. The judgment method comprises the steps that sampling voltage is converted from a three-phase stationary coordinate system to a two-phase rotating coordinate system; in the two-phase rotating coordinate system, a d-axis direct current voltage component Ud and a q-axis direct current voltage component Uq are decoupled and separated; and the d-axis direct current voltage component Ud and the q-axis direct current voltage component Uq are filtered to acquire a d-axis direct current voltage component Ud flt and a q-axis direct current voltage component Uq flt, and the d-axis direct current voltage component Ud flt and the q-axis direct current voltage component Uq flt are used to judge whether the power grid voltage drops. According to the invention, the system is rapidly controlled and protected by improving the rapidity and accuracy of the system to judge the states of voltage drop and recovery.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a method and system for judging the drop state of a three-phase AC voltage. Background technique [0002] Due to problems such as environmental impact, geographical restrictions and resource scarcity, power generation has gradually reduced its dependence on primary energy generation, and realized the optimal allocation of global energy. Hydropower, wind power, photovoltaic power generation, biomass power generation, ocean energy A series of new renewable energy sources such as power generation and geothermal power generation have become research hotspots. The development of renewable energy is also accompanied by its characteristics of randomness, intermittency, volatility and unpredictability. When it is connected to the power system on a large scale, it will bring great harm to the stability, reliability and power quality of the power system. influences. [0003] En...

Claims

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Application Information

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IPC IPC(8): G01R19/165
CPCG01R19/16528
Inventor 庄俊陶以彬姚良忠杨波李官军周晨余豪杰胡安平曹远志刘欢鄢盛驰桑丙玉崔红芬冯鑫振薛金花陶琼韩桂刚侯书毅卢俊锋李跃龙朱红保马鑫鑫
Owner CHINA ELECTRIC POWER RES INST
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