Open AccessDifferent approaches to modelling single‐phase voltage source inverters for uninterruptible power supply systems
Author(s) -
Rymarski Zbigniew,
Bernacki Krzysztof
Publication year - 2016
Publication title -
iet power electronics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.637
H-Index - 77
eISSN - 1755-4543
pISSN - 1755-4535
DOI - 10.1049/iet-pel.2015.0142
Subject(s) - uninterruptible power supply , control theory (sociology) , pulse width modulation , inductance , inverter , filter (signal processing) , voltage source , electromagnetic coil , electronic engineering , voltage , engineering , computer science , electrical engineering , control (management) , artificial intelligence
The standard single‐phase three‐level voltage source inverter (VSI) for uninterruptible power supply systems consist of a pulse width modulation (PWM) modulator, an H‐bridge, and an output inductance/capacitance filter. The design of most control systems requires the inverter small‐signal model. Two approaches for the discrete modelling of the VSI can be considered. The first is based on solving the state space equations during the switching period, which yields a discrete model that depends on the single‐edge or double‐edge type of PWM model. The second approach is the based on the continuous model of the inverter, which is derived from measurements of the real inverter and its discretisation. Both models should regard the increase in the real value of the equivalent coil series resistance and changes in the filter coil inductance with the frequency and amplitude of the magnetising current. The design of the control system requires experimental estimation of the additional delays, which are outside of the models during the measurements and modelling. Both models are validated by comparing the closed‐loop systems with the simple instantaneous controllers in the experimental model.