Predictive current control of multi-leg neutral-point piloted converter

Abstract

The neutral-point piloted (NPP) converter with bidirectional switches produces less switching losses than the neutral-point clamped converter while preserving best qualities of multilevel operation. This paper proposes NPP converter for multiphase power conversion applications. The discrete-time modeling of NPP converter load currents and DC capacitors voltage is presented in terms of switching states. A generalized procedure for the predictive current control (PCC) of two-leg, three-leg, four-leg and five-leg NPP converters is presented. The simulation results validate that the PCC scheme forces the load currents to track their reference currents with less steady-state error and fast transient response while maintaining the DC capacitors voltage balanced during all operating conditions.