On the Tuning of Fractional Order Resonant Controllers for a Voltage Source Converter in a Weak AC Grid Context

Haro-Larrode, Marta (Universidad de Zaragoza) ; Bergna-Diaz, Gilbert ; Eguia, Pablo ; Santos-Mugica, Maider

Resumen: This paper proposes a method for tuning the fractional exponent of different types of fractional order resonant controllers for a voltage source converter in a weak AC grid context. The main objective is to ensure the stability of the controlled system in a weak AC grid environment and to achieve an adequate dynamic response under disturbances. Therefore, six commonly used integer order proportional resonant (PR) control structures are selected from the literature and compared with each other according to their frequency behaviour. Afterwards, a rational approximation for the fractional order term is selected based on continuous fraction expansion technique. The inclusion of a fractional exponent in each integer order PR structure generates the fractional order proportional resonant (FPR) control transfer functions. Once the FPR controllers have been obtained, their closed-loop responses are tested via eigenvalue trajectory analysis. For each FPR control structure, a range of the fractional exponent that ensures stability is obtained. The conclusions of eigenvalue trajectory analysis are tested by implementing the FPR control structures in an specific application consisting in a modular multi-level converter (MMC) connected to a weak AC grid with adjustable short-circuit ratio. By means of time-domain simulations, not only the previous eigenvalue analyses are validated, but also new tuning criteria are given for the fractional exponent in combination with other control parameters, such as the damping frequency and the inductance of the complementary feedback branch. Moreover, a sensitivity analysis of the tuning criteria is carried out for other sizes of the AC filter inductance.

Idioma: Inglés

DOI: 10.1109/ACCESS.2021.3069444

Año: 2021

Publicado en: IEEE Access 9 (2021), 52741-52758
ISSN: 2169-3536

Factor impacto JCR: 3.476 (2021)

Categ. JCR: COMPUTER SCIENCE, INFORMATION SYSTEMS rank: 79 / 163 = 0.485 (2021) - Q2 - T2
Categ. JCR: TELECOMMUNICATIONS rank: 43 / 92 = 0.467 (2021) - Q2 - T2
Categ. JCR: ENGINEERING, ELECTRICAL & ELECTRONIC rank: 105 / 274 = 0.383 (2021) - Q2 - T2

Factor impacto CITESCORE: 6.7 - Engineering (Q1) - Computer Science (Q1) - Materials Science (Q1)

Factor impacto SCIMAGO: 0.927 - Engineering (miscellaneous) (Q1) - Computer Science (miscellaneous) (Q1)

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Ingeniería Eléctrica (Dpto. Ingeniería Eléctrica)