The dynamic properties of a single-phase transformer-based inverter for ups systems

摘要

This paper presents two algorithms for the creation of an analytical model of a single-phase transformer-based inverter, using either the measurements of the control frequency-dependent characteristics of the inverter or the initial in-circuit frequency-dependent measurements of the transformer. The paper discusses how the parameters of the line transformer influence the dynamic properties of the inverter and, as a consequence, the design of the instantaneous control feedback loop. Line transformers, widely used in industry, have not yet been analysed for use at higher than normal operating frequencies. The basic parameters of the transformer are the nonlinear functions of the primary voltage amplitude and frequency. The paper includes verification of both methods using the breadboard experimental model. In the final step, the inverter control transfer functions are calculated. To show the utility of both models, an exemplary discrete controller for the experimental inverter model has been designed and tested. Copyright (c) 2015 John Wiley & Sons, Ltd.