Sliding Mode Observation of capacitor voltage in multilevel power converters

In this paper a sliding mode observer is designed and applied to a two-port multi-cellular power converter topology in order to observe the DC-link capacitor voltages. Among different sliding mode observers, the Sliding Mode Observer (SMO) using equivalent control approach has been selected for use because of its robustness against uncertainties in system equations. Simulation is carried out using SABER software. For practical results the controller is implemented on a TMS320C6713 DSP and two ACTEL FPGAs. The observer equations are implemented on an FPGA using a fixed-point system programmed in VHDL.