Patent ID: 7558089
Filing Date: 2009-07-07
Classification: H02M

Abstract:
1. An apparatus for space vector modulation of a multi-level inverter, said apparatus comprising: a triangle generator for finding a modulation triangle enclosing a reference voltage vector, said modulation triangle comprising vertex vectors; a duty ratio calculator for determining duty ratios for said vertex vectors; a forbidden transition identifier for identifying a forbidden transition between two of said vertex vectors; a control module for applying said switching functions to said multi-level inverter according to said duty ratios and avoiding said forbidden transition; and a switching function selector for selecting switching functions corresponding to said vertex vectors, wherein said switching function selector comprises: a vertex level computer for computing vertex levels corresponding to said vertex vectors, each of said vertex vectors being described by a respective skew coordinate pair, (G, H), each of said vertex levels, L, being computed according to the rule: and “abs( )” denotes the absolute value function: a triangle level computer for computing a triangle level, K, equal to the maximum of said vertex levels; a switching function computer for computing said switching functions, each of said switching functions, V, being computed according to the rule: