Grid inductance estimation by reactive power perturbation for sensor-less scheme based on virtual flux

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Journal Title
Journal ISSN
Volume Title
A4 Artikkeli konferenssijulkaisussa
Date
2008
Department
Major/Subject
Mcode
Degree programme
Language
en
Pages
7
Series
Proceedings of the Nordic Workshop on Power and Industrial Electronics (NORPIE/2008)
Abstract
Use of renewable energy sources is raising for grid connected systems, for which higher power quality requirements are being issued. Monitoring the grid impedance ensure stable operation of the controller and proper connection and disconnection from the grid. Thus it is vital to know the value of grid or transformer distributed impedance in given time, instead assuming a constant value in controller. To overcome this problem an identification method based on perturbation of reactive power is proposed. The normally inductive character of the grid used together with synchronous frame current controller have cross coupling terms which are used in analysis. This method is suitable for use with virtual flux oriented control. It uses two current sensors and one dc link voltage sensor. Method enables maintain unity power factor not only at PCC but also further into the grid, including lines and transformer leakage inductance.
Description
Keywords
grid impedance, renewably energy, virtual flux, VSC control
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Citation
Permanent link to this item
https://urn.fi/urn:nbn:fi:tkk-011642