Average Model-Based Feedforward and Feedback Control for PUC5 Inverter

Abstract

This paper proposes new average model based control strategies for a 5-level Packed U-cell (PUC5) inverter in both standalone and grid-connected modes of operation. First, a simple feedforward controller (FFC) is designed, using only two pulse width modulation (PWM) carrier signals, for the PUC5 inverter operating in standalone mode. This proposed control technique ensures self-balanced operation with high steady-state performance. Moreover, the employment of the proposed FFC leads to a decrease in the capacitor's value as well as the minimization of the Total Harmonic Distortion (THD). Then, a feedback linearizing control technique is designed to improve the transient and steady-state performances. In grid-connected mode, a reduced-sensor technique based on the FFC and the state feedback (FC) techniques was applied. Simulations and experimental results are presented to prove the high performance of the proposed solutions for standalone and grid-connected operating modes.

Keywords

• Packed U-cell inverter
• PUC5
• self-balancing
• average model
• feedback linearizing
• feedforward control