Implementing Synchronous Dc Link Voltage Control With Phase Skipping On A Three-Phase Microinverter Using Minimum Dc Link Capacitance

Keywords

DC bus; DC link voltage control; Minimizing DC link capacitance; Three-phase microinverters

Abstract

To improve light load efficiency, a three-phase photovoltaic (PV) based microinverter may operate in singlephase, two-phase or three-phase mode depending on the available input power. Therefore, its DC link capacitor may be subjected to large peak-to-peak voltage ripple when operating in phase skipping mode. This paper determines the minimum value of the DC link capacitor by allowing the maximum acceptable voltage ripple on the DC link. This allows for the use of film capacitors instead of electrolytic capacitors in order to improve the microinverter reliability. It is proposed that a simple synchronous control method can be used to regulate the DC link voltage with the presence of large voltage ripple. The DC link voltage controller is synchronized with the phase-locked loop and samples the average value of DC link voltage without introducing unwanted harmonics into the voltage sense path. A 300-W threephase microinverter prototype was built to verify the proposed DC link voltage control performance. Inverter output current total harmonic distortion of 1.6% was achieved even though the DC link peak-to-peak voltage ripple reached as high as 87 V with 219 V split DC link voltage. Dynamic response is fast enough to easily track the most extreme ramp change in input PV power.

Publication Date

11-3-2017

Publication Title

2017 IEEE Energy Conversion Congress and Exposition, ECCE 2017

Volume

2017-January

Number of Pages

175-182

Document Type

Article; Proceedings Paper

Personal Identifier

scopus

DOI Link

https://doi.org/10.1109/ECCE.2017.8095778

Socpus ID

85041279913 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/85041279913

This document is currently not available here.

Share

COinS