Vector control of single-phase voltage source converters based on Fictive Axis Emulation

Abstract

This paper presents an alternative way for controlling the current of single-phase voltage source dc-ac inverters in a dq synchronous reference frame. In a dq reference frame, ac (time varying) quantities appear as dc (time invariant) quantities allowing the controller to be designed as for dc-dc converters presenting infinite control gain at the steady-state operating point to achieve zero steady state error. The common approach is to create a set of imaginary quantities orthogonal to those of the real single-phase system so as to obtain dc quantities by means of a stationary to rotating frame transformation. The orthogonal imaginary quantities in common approaches are obtained by phase shifting the real components by a quarter of the fundamental period. The introduction of such delay in the system deteriorates the dynamic response, which becomes slower and oscillatory. In the proposed approach of this paper, the orthogonal quantities are generated by an imaginary system called Fictive Axis, which runs concurrently with the real one. The proposed approach, which is referred to as Fictive Axis Emulation (FAE), effectively improves the poor dynamics of the conventional approaches while does not add excessive complexity to the controller structure.

Superior decoupled control of active and reactive power for three-phase voltage source converters

“…In this section, the mathematical model of the three-phase test system and its structure diagram is derived [30]. Based on Figure 1, which shows the structure of the test system, writing the KVL from the PCC bus to the converter terminal results in the dynamic equation of the VSC in the abc frame as below:…”

Advanced Control Strategy for Single–Phase Voltage–Source Active Rectifier with Low Harmonic Emission

“…This power converter allows the precise control of DC-link voltage U c to constant value and the current control on ac side of converter i t (the quality of flowing current is very dependent on selected control). Control of the active rectifier is a very popular issue and it is possible to find many interesting articles with different control methods: i) hysteresis control method [1,2], ii) model based control [3,4], iii) vector control [5], iv) direct current control based on PR controller [6,7]. This type of power converter (H-bridge) is basic component for multilevel power converters [8][9][10][11] and especially for multilevel traction converter [12][13][14].…”