A Robust Ultra-Local Model Control with DC Capacitor Voltage-Balancing for PEC9 Inverter

With seven switching devices and two capacitors, the configuration of PEC9 has significantly decreased the number of ingredients in a creative topology. By proper regulation of the PEC9, this inverter provides various levels of voltage under a faulty switch state, which is the most prominent feature of such inverters. In this paper, an ultra-local mode control (ULM) based on single input interval type-2 (SIIT2) fuzzy logic control (FLC) is proposed in a model-free framework to stabilize the inverter output without the model identification. The control structure is divided into two sections: i) a ULM controller is adopted to meet the primary control requirements of the system operation while an extended observer error (ESO) is embedded to estimate the unknown uncertainty included in the inverter, ii) a supplementary SIT2-FLC controller is established to decrease the ESO error and improve the performance of PEC9 operation accordingly. The time-domain outcomes are provided and discussed to appraise the simplicity of control design and superior feasibility of the suggested scheme than the state-of-the-art approaches.