A Novel Space Vector Technique for the Direct Three-level Matrix Converter

Abstract

This study proposes a novel Direct Torque Control (DTC) method for the Direct Three level Matrix Converter (DTMC), which uses both the input phase voltage vectors (short vectors) and the input line voltage vectors (long vectors). The problem of voltage imbalance at the input filter capacitance due to the use of the short vectors is addressed with an additional voltage hysteresis comparator. With the errors of torque, flux, sin Ψ and the neutral point voltage, an Optimum Switching Table (OST) is designed for the DTMC. The OST generates the necessary switching signals for the DTC of the DTMC. The DTMC topology with the modified ISVM technique reduces the THD at the output. The proposed DTMC Indirect Space Vector pulse width Modulation (ISVM) technique uses the idea of multilevel inverter SVM technique along with the proposed neutral current balancing strategy for generating the firing pulses. The switching loss model for the DTMC is developed and the performance of the DTMC is compared with that of the Conventional Matrix Converter (CMC). The performance of the proposed DTC technique for the DTMC is evaluated through simulation to explain the reduced torque ripple characteristics. To validate the proposed DTMC ISVM technique, a 3 kVA direct multilevel matrix converter prototype was developed.