Balance control method for common-mode voltage and neutral point voltage of T-type three-level inverter

• Main Authors: ZOU HAIRONG, LI QIN, DING SHAOYUN, PAN SANBO
• Format: Patent
• Language: Chinese; English
• Published: 24.08.2021
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION

The invention relates to a balance control method for common-mode voltage and neutral point voltage of a T-type three-level inverter, which comprises the following steps of: firstly, dividing a three-phase space vector of the T-type three-level inverter into six large sectors, and classifying each vector into a large vector, a medium vector, a small vector and a zero vector according to the amplitude; then selecting six medium vectors, one zero vector and six virtual small vectors as basic vectors of a novel virtual vector modulation strategy, dividing a three-phase space vector into twelve sectors again through the novel virtual vectors, adopting five-section symmetrical wave sending, and establishing overall calculation in a 60-degree coordinate system. Compared with the prior art, the method has the advantages that the implementation difficulty of suppressing the common-mode voltage is simplified, the voltage fluctuation of the neutral point is well suppressed, and the overall calculation amount is small.