Fundamental voltage synchronous signal detection method during harmonic distortion and unbalance of network voltage

A technology of power grid voltage and harmonic distortion, applied in the direction of measuring current/voltage, phase angle between voltage and current, measuring electrical variables, etc., can solve problems such as difficult effective adjustment of AC components, affecting detection results, etc., and meet hardware requirements Low, reliable control benchmark, easy engineering effect

Inactive Publication Date: 2012-01-04
ZHEJIANG UNIV
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Problems solved by technology

The PI controller used in the traditional PLL is limited by the adjustment bandwidth and gain margin, and it is difficult to effectively adjust the AC component, which leads to the fluc

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  • Fundamental voltage synchronous signal detection method during harmonic distortion and unbalance of network voltage
  • Fundamental voltage synchronous signal detection method during harmonic distortion and unbalance of network voltage
  • Fundamental voltage synchronous signal detection method during harmonic distortion and unbalance of network voltage

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Embodiment Construction

[0039] The present invention provides a detection method for grid voltage harmonic distortion and unbalanced time fundamental voltage synchronization signal which is relatively simple in engineering implementation. The method only needs to add two resonant frequencies to the conventional PLL, which are 2 times and 6 times the grid frequency respectively. The resonant compensator can effectively reduce the influence of grid voltage harmonics and negative sequence components on fundamental voltage frequency, phase and amplitude detection. At the same time, when the three-phase grid voltage is symmetrical, the output of the added resonant compensator is zero, which will not affect the steady-state performance of the PLL and will not hinder the detection effect under normal grid conditions, so it has strong robustness. In addition, the present invention also provides a phase sequence decomposition method based on a multi-frequency notch filter, which can accurately separate the pos...

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Abstract

The invention discloses a fundamental voltage synchronous signal detection method during harmonic distortion and unbalance of network voltage. A novel resonant phase locked loop (PLL) can quickly compensate phase tracking errors caused by various network faults, effectively inhibit frequency fluctuation and phase jitter caused by a negative sequence and a harmonic component in the network voltage, and realize accurate detection of fundamental voltage synchronous signals in a distorted network. The method can meet the detection requirements on voltage frequency, amplitude and phase under the ideal network conditions, is particularly suitable for capturing the fundamental voltage synchronous signals under severe transient state and stable state network faults such as network voltage drop, unbalance, harmonic pollution and the like, and can realize quick extraction of the positive and negative sequences and the harmonic component in the voltage. The method has the characteristics of highdetection accuracy and good real-time property, can provide an accurate control basis for operating control of grid-connected power equipment such as various wind generating sets, solar photovoltaic grid-connected devices, reversible speed control transmission systems, dynamic reactive compensators and the like.

Description

technical field [0001] The invention relates to a method for detecting the fundamental wave voltage synchronous signal when the grid voltage is harmonically distorted and unbalanced. It is suitable for the enhanced operation capability control of wind turbines under non-ideal grid conditions, and the rapid acquisition of the grid fundamental wave voltage phase, amplitude and frequency required for high-performance control of four-quadrant reversible AC speed control drive systems. Background technique [0002] In recent years, with the wide application of power electronic equipment such as uncontrolled rectifiers, irreversible AC speed-adjusting transmission systems, reactive power compensation devices, solar photovoltaic power generation grid-connected inverters, and single-phase electric locomotives, the grid voltage Harmonic pollution and three-phase unbalance problems are becoming more and more serious, resulting in grid voltage and current waveform distortion and the ge...

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Application Information

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IPC IPC(8): G01R19/00G01R25/00G01R23/02
Inventor 徐海亮贺益康周鹏章玮
Owner ZHEJIANG UNIV
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