A Novel Self-Balanced Thirteen-Level Switched-Capacitor Multiphase Inverter for Solar PV Applications

This paper proposes a new self-balanced thirteen-phase switched-capacitor multi-phaseinverter custom-made to solar photovoltaic (PV) systems. The inverter has been made to suchan extent that it helps avoid the use of complex control algorithms, ancillary sensors andbalancing circuits, which are normally used to ensure fair, equitable distribution of voltages inall the capacitors. The performance of the inverter is evaluated in the steady state and dynamicoperations regime in three stage switched-capacitor cell architecture, which is controlled bypulse-width modulation (PWM). When the inverter operates under PWM, the inverter is ableto boost high voltages in its operation whilst maintaining constant capacitive voltages. Thetopology suggested increases the level of output voltage that can be attained and it ensures thesimilarity in terms of voltage distribution across all the capacitors, which enhances systemoperation reliability and efficiency. Simulation in MATLAB/Simulink has been conducted toperform performance validation. The results of the simulation show a voltage gain of 6.0,maximum efficiency of 96.7% and a total harmonic distortion (THD) of 3.21%. Additionally,the capacitor voltage variations are very limited to a range of 0.5 to 1 hence, supporting theefficacy of voltage control and prompt transient response behaviours. In addition, the inherentinverter setting reduces common-mode voltage and thus suppresses electromagneticinterference and thus increases system reliability. Relative increases on the traditional hybridswitched-capacitor inverters and cascaded H-bridge multilevel inverters also support the highbenefits of the current design as compared to voltage enhancement ability, harmonic response,and self-balancing of capacitor voltage. Small size, reduced number of switches, highefficiency, and excellent quality of output voltage of the proposed thirteen-level switchedcapacitor multi-phase inverter make it attractive as an option to future generation PV-poweredrenewable energy systems and high-performance motor drive systems.