| MS Seminar

Name of the Speaker: Mr. P SRI CHAITANYA (EE17S048)
Guide: Dr. Krishna Vasudevan
Online meeting link: http://meet.google.com/inc-gqhg-rgb
Date/Time: 6th November 2025 (Thursday), 3:00 PM
Title: Modeling Of PSFB Converter Integrated With Inverter working in the Grid-Tied PV Applications.

Abstract :

The increase in global demand for reliable, clean, and sustainable energy has increased the development and implementation of renewable energy systems. Among the various renewable energy sources, solar energy related photo-voltaic (PV) technology has emerged as a leading solution due to abundance, less cost etc.

The inherent time varying nature of solar irradiation pose a major challenge for supplying stable power in both standalone systems and grid connected applications. To address these challenges mentioned, microgrids with suitable control are gaining attention for integrating distributed energy resources (DERs), which include photo-voltaic systems, wind turbines, hydel power etc. These enable independent control and optimized operation in both grid-connected and islanded modes.

One of the most popular converter for high frequency, high power density and medium to high power applications is the phase shifted full bridge (PSFB) converter due to its inherent characteristic of soft switching without using additional auxiliary circuit. In this study the DC/DC (PSFB) converter integrated to inverter in grid tied PV applications is considered from a modeling perspective. Analysis of the PSFB converters in literature usually consider a fixed dc bus voltage source with the load treated as a fixed resistance. However when fed from a solar PV array the input to the converter is not a fixed dc source. The PSFB output is connected to the inverter powering grid, and hence is not a fixed resistance load. Better models are therefore needed for system analysis and control system designs.

In this work, the PV array is modeled as a current source (dependent on load, irradiation and cell temperature) and inverter (working in grid-tied control) as a current sink at the PSFB output. Small signal models relating duty to input PV voltage are derived and validated which are then used for tracking MPP power. Due to intermittent nature of irradiation, there is a disturbance propagated in the system, which are seen on the DC bus as (due to active power mismatch) voltage variations. Therefore, models describing response to disturbances are needed for proper design to attenuate the disturbance.

Finally, a 12kW hardware of the PSFB converter is tested to validate the model derived along with the closed loop control presenting the tracking efficiency.