多电平变换器的一种参考电压矢量自校正策略

For multi-level converters, the usual circuit topologies include diode-clamped, flying capacitor, cascade H-bridge and t-type, etc. These topologies have many switching states, control objectives and nonlinear problems, causing deviates of the PWM modulation reference voltage vector instruction. Firstly, based on the T type three-level converters, in the vector space, according to the amplitude and position of the corresponding voltage vector, the paper summarized deviation calculation rules of the dead time voltage vector, and proposed an adaptive correction method of reference voltage vector instructions. Secondly, the four-level diode clamp topology and T-type five-level topology were taken as examples to analyze the application and effectiveness of this method in more level converters. The switch dead time effect was suppressed, and the pulse loss or saturation problems of the traditional PWM pulse shaping was solved. Further, by setting the relation function of voltage error, switching state and load current direction, the general correction formula of the method was obtained in this paper. The reference voltage vector instruction is improved and experimental results verifiy the effectiveness of the algorithm.