Discrete modelling and state‐mutation analysis for sliding mode controlled non‐isolated grid‐connected inverter with H6‐type

Abstract

To analyse stability and non-linear behaviour of the sliding mode controlled non-isolated grid-connected inverter with H6-type (SMCNGCI-H6) system, the discrete model of the SMCNGCI-H6 system is first established based on the quasi-static theory and stroboscopic map method. With the case of folded diagram, a particular non-linear behaviour (state-mutation phenomenon) is observed that the state variable changes from the period-1 state to the period-2 state at a certain switching cycle. Then the root cause of state-mutation phenomenon is explored. Meanwhile, regarding the variation of state-mutation switching cycle with the parameters of sliding mode controller (SMC), a novel criterion (state-mutation switching cycle criterion) is proposed to determine state-mutation switching cycle of the state variable. Finally, the simulation and experimental results prove the validity of the discrete modelling of SMCNGCI-H6 system and the state-mutation switching cycle criterion.