Grid fault is a challenge for electrical equipments in operating and control stably. In order to enhance the reliable operation of network equipments, grid frequency, phase angle and amplitude tracking must be fast dynamic respond performance and high detection accuracy under various grid faults. So that the appropriate control measures can be taken timely. This paper presents a new method to achieve real-time detection and tracking of voltage phase angle jumping, at the same time extract positive and negative sequence instantaneous components, based on the existing phase detecting technique and the synchronous reference frame method. The principle of which is calculation by use of the present voltage or current components on d-q synchronous rotating coordinate system and the corresponding variables a sampling time before. So the method of acquiring the phase angle jumping value under grid faults has strong capacity, either can be used for instantaneous analyses of balanced faults or used for instantaneous analyses of unbalanced faults. In addition, it is important to promote operation control strategy for grid connected electrical equipments. As an example, it can be used in LVRT (Low Voltage Ride-Through) control for wind power development. The simulation results verify the advantages of the proposed method including: good real-time performance, suitable for the application of practical engineering, solving the problem of traditional symmetrical components only suitable for steady-state analyses of unbalanced faults and systems, without multiple complex calculations.
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