Measurement-Based Identification of DC-Link Capacitance of Single-Phase Power Electronic Devices for Grey-Box Modeling

This article presents a non-destructive measurement-based identification of the dc-link capacitance in single-phase power electronic devices for modeling purposes. These devices are typically found in public low voltage networks for low power applications. A large number of manufacturers of these devices with individual approaches to the design of the components of the power electronic devices challenges the modeling and thus the analysis of their interaction with other devices and the low voltage network. Since the manufacturers typically do not disclose their design, only little information based on the assumptions can be made with regard to an individual device. This article provides a new method to identify the dc-link capacitance of single-phase power electronic devices based on analyzing the ripple part of the dc-link voltage, which contributes to the present research activities toward realistic modeling of such devices for power systems studies. The analytical background is provided and a simulative validation is performed. Finally, a laboratory application to a commercially available single-phase inverter for photovoltaic systems is demonstrated in terms of real measurement.