Impedance-Based Stability and Transient-Performance Assessment Applying Maximum Peak Criteria

Abstract

Abstract-The impedance-based stability-assessment method has turned out to be a very effective tool and its usage is rapidly growing in different applications ranging from the conventional interconnected dc/dc systems to the grid-connected renewable energy systems. The results are sometime given as a certain forbidden region in the complex plane out of which the impedance ratioknown as minor-loop gain-shall stay for ensuring robust stability. This letter discusses the circle-like forbidden region occupying minimum area in the complex plane, defined by applying maximum peak criteria, which is well-known theory in control engineering. The investigation shows that the circle-like forbidden region will ensure robust stability only if the impedance-based minor-loop gain is determined at the very input or output of each subsystem within the interconnected system. Experimental evidence is provided based on a small-scale dc/dc distributed system.

Control strategies for 2-quadrant converter used in grid power flow control

“…In each case, the energy variation is related to the maximum reactive energy in the magnet, E m = 1/2L m I 2 ref . It can be observed that the maximum energy variation of the storage element in strategy EB corresponds to the maximum reactive energy in the magnet, which is a consequence of the energy balance shown in (2). In strategy GCBP, the energy variation is greater than in the case of strategy EB, since during magnet pulse generation the capacitor C st must supply both the reactive energy and the active energy.…”

“…Additionally, a proper design of the input filter avoids that the H-bridge input current affects the voltage v dc and, hence, avoids stability issues [2,3,4]. Then, the simplified circuit of the Fig.…”

Review of PV Generator as an Input Source for Power Electronic Converters

“…The analysis methods are developed further in many publications (e.g., [28,42,[117][118][119][120][121][122][123][124][125][126][127]). The further developments are mainly concentrated on enlarging of the allowed area in complex plane, where the impedance ratio is allowed to lie without causing instability [117,118,122], on making the special parameters governing the interactions in the converters to be explicitly solvable [119,122], and on extending the methods into the grid-connected three-phase converters as well [123][124][125][126][127].…”

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