A Novel SVPWM Algorithm for Five-Level Active Neutral-Point-Clamped Converter

The five-level active neutral-point-clamped (5L-ANPC) converter is becoming an attractive topology of multilevel converter family. A novel SVPWM algorithm based on line voltage coordinate was studied in this paper to overcome shortcomings of the traditional algorithm. Through coordinate transformation, steps of determining the basic vectors and the solution about the basic vector corresponding action time are simplified. Combining with the characteristics of 5L-ANPC converter and the new control algorithm, a method of controlling the voltage balancing of dc-link capacitors and floating-capacitors is proposed. According to the voltage of dc-link capacitors, the suitable switching sequence which can balance the voltage of dc-link capacitors is chosen. The high common-mode voltage will affect the service life of motor and reduce the reliability of the system especially in high-voltage converter. The common-mode voltage is also reduced by choosing the right switching state in this paper. The validity of the proposed method was proved by the experimental results.