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

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...

AI Technical Summary

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 fluctuation of the output voltage amplitude and frequency and the jitter of the phase lock angle in the synchronous rotating coordinate system, which seriously affects the Detection effect

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