Other

Tianzhen Wang

Zhuo Liu

Han Wang

Jingang Han

Chao Geng

The present invention provides an adaptively modulated multi-state inverter system, comprising: a split capacitor, four bridge arms and an isolation switch group, on each of the four bridge arms a pair of complementary power switch groups is arranged; the isolation switch group comprises four fuses and six bidirectional thyristors. The output branches of the first bridge arm, the second bridge arm and the third bridge arm are respectively connected in series with a fuse to output a three-phase voltage, and at three-phase output voltage side two shared auxiliary branches are arranged, one auxiliary branch starts from the fourth bridge arm output branch on which a fuse is connected in series and is then connected to the output terminal of the three-phase voltage via three bidirectional thyristors. The other auxiliary branch starts from the DC side feed branch from the midpoint of the split capacitor, and is connected with the output terminal of the three-phase voltage via three bidirectional thyristors respectively. The invention also provides a modulating method of the multi-state inverter system. The use of the adaptive modulating technology enables the multi-state inverter to have the functions of overcurrent protection, isolation of faulty bridge arms and fault-tolerant control on any single and double bridges.

Adaptively modulated multi-state inverter system and modulating method thereof

The present invention discloses a voltage reference reconfiguration fault-tolerant control method for a cascaded multi-level inverter. The fault-tolerant method for the inverter automatically reconfigures the three-phase voltage amplitudes and phases of the three-phase total voltage in accordance with the fault diagnosis, thus realizing three-phase voltage balance. On the basis of the reconfiguration of the total voltage signal, re-reconfiguration of reference voltage inputted into the various H-bridges is conducted in accordance with the fault signal vectors, thereby realizing removal of the fault bridges and fault-tolerance of the normal bridges, while guaranteeing the integral sinusoidal characteristics of the actual reference voltage. The inverter realized maximum three-phase balanced line voltage in a fault occurrence, has the advantages of requiring no redundant modules and algorithms and the advantages of ease of removing fault bridges, and is applicable for reduced load operable electrical equipment.

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Shanghai, China

Tianzhen Wang