Physics Maths Engineering

Design of PFC converter with stand-alone inverter for microgrid applications



  Peer Reviewed

Abstract

AbstractThe proposed topology is used to connect a single-phase and a three-phase renewable energy resources to the grid. The single-phase source is coupled to a single-phase PFC boost converter, which enhances the input PF utilizing two feedback loops: outer voltage loop control and inner current loop control. The basic hightlight is to study the PFC converter in microgrid application where renewables are integrated with the systems. The basic aim is to observe the overall performance of the converters with various disturbances such as load variations, etc. Here, the single-phase and three-phase stand-alone inverter is used to get the the output of the PFC boost converters. A symmetrical sinusoidal output voltage waveform should be produced and maintained by the inverter. The three-phase source is also coupled to a PFC buck converter, which enhances the input PF utilizing two feedback loops: outer voltage loop control and inner current loop control. The single-phase stand-alone inverter receives the output of the PFC buck converter. The transformer receives the outputs of both the inverters as it is a multi-winding high-frequency transformer and offers isolation between the grid and the source. The pulses for the switches in the single-phase inverter coupled stand-alone system were generated using a sinusoidal pulse width modulation approach. Both the PI controllers are implemented to maintain the regulations. The simulation results are achieved by varying the load, maintaining a constant voltage, and observing whether the current varies as the load changes. It also provides the efficacy of the study.

Key Questions

What is the purpose of the proposed topology?

The topology is designed to connect single-phase and three-phase renewable energy sources to the grid, improving power factor and regulating voltage.

How does the PFC converter improve performance?

The Power Factor Correction (PFC) converters enhance the input power factor through dual feedback loops—outer voltage and inner current loops.

What are the key components in the system?

The system includes a PFC boost converter, PFC buck converter, stand-alone inverters, and a multi-winding high-frequency transformer for isolation.

How is the inverter's output voltage regulated?

The inverter output is maintained as sinusoidal using unipolar PWM switching and regulated by PI controllers.

What types of disturbances were studied in the simulations?

The study examined performance under varying load conditions and disturbances to evaluate the efficacy of the converters in maintaining stable output.

What role does the high-frequency transformer play?

The transformer provides isolation between the grid and the source, ensuring safety and improved performance in power distribution.