Open AccessStability and bifurcations in low inertia PV rich power networks
Author(s) -
Vinaya Mohanan Vishnu A.,
Mareels Iven M. Y.,
Evans Robin J.,
Morton Anthony B.,
Kolluri Ramachandra Rao
Publication year - 2020
Publication title -
iet generation, transmission and distribution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.92
H-Index - 110
eISSN - 1751-8695
pISSN - 1751-8687
DOI - 10.1049/iet-gtd.2019.1797
Subject(s) - photovoltaic system , control theory (sociology) , inertia , grid , grid connected photovoltaic power system , power (physics) , stability (learning theory) , computer science , topology (electrical circuits) , maximum power point tracking , voltage , engineering , mathematics , physics , electrical engineering , inverter , control (management) , classical mechanics , artificial intelligence , machine learning , geometry , quantum mechanics
The present trend of inserting increasingly more solar photovoltaic (PV) sources into the electricity grid leads to a significant reduction in mechanical inertia. Inertia represents energy reserve in the grid, that inherently and instantaneously supports frequency stability. Therefore, recent studies have re‐examined the frequency stability of the grid. Most of these consider scenarios where the participation from grid‐following inverters remains relatively low. More importantly, these studies include an infinite bus in their analyses. The infinite bus acts as a very stiff voltage source which has a significantly stabilising influence, the more so as all control refers back to the infinite bus. Here, the frequency stability of a grid with significant generation from grid‐tied PV inverters is considered without reference to an infinite bus. In the proposed simplified grid model, all the synchronous generators (SGs) are lumped as one large SG complete with classically operating controls. Similarly, all the PV generators are lumped as one large, quasi‐instantaneous, non‐linear power source. In this simplified network, the feasible operating region is identified using bifurcation techniques. It transpires that the stable operating region is bounded by a locus of Hopf bifurcations linked (inter‐alia) to the fraction of power generated by grid‐tied PV inverters.