DSP-based universal space vector modulator for multilevel voltage-source inverters

A novel simple, fast and generally applicable multilevel space vector modulation (SVM) algorithm is proposed in this paper. The reference voltage vector is decomposed into offset vector and two-level vector. Thus a complicated multilevel SVM issue is simplified into a simple two-level SVM issue. The switching states and their duty cycle are determined based on the zero-sequence reference voltage and a good combination of switching states selection and optimal control of inverters is reached. The proposed algorithm is very simple, fast and applicable for any number of levels. Based on the proposed SVM algorithm, a DSP-based universal space-vector modulator for multilevel inverters is developed. The validity of the proposed algorithm and the developed modulator is verified by the test results of various numbers of levels. It is also verified using a 6 kV/1800 kVA three-level inverter system.