A virtual voltage vector based direct torque control (DTC) scheme with enhanced DC bus utilization for an asymmetrical six-phase induction motor (ASPIM) with open-end stator windings is proposed in this paper. In this scheme, the voltage vectors generated by two six-phase, two-level voltage source inverters (VSI) connected to both sides of the stator windings are combined to obtain a virtual voltage (VV) space vector structure in the ASPIM. While generating the virtual voltage vectors it is ensured that the following three conditions prevails in the system: 1) elimination of resultant common mode voltage (CMV) across the stator windings, 2) elimination of triplen order harmonic voltages from the individual 3-phase windings, and 3) nullification of non-torque producing harmonic voltages. Conditions 1 and 2 facilitate the use of a common DC-link for both the VSIs without causing circulation of common mode currents through the stator windings. The third condition obliterates the large, non-torque-producing harmonic currents and consequent losses in the system. The proposed scheme can provide significantly higher DC bus utilization compared to the conventional schemes, for the same DC-link voltage. The effectiveness of the proposed scheme is verified by carrying out simulations using MATLAB-Simulink software, under transient and steady-state operating conditions of the drive.
Virtual Voltage Vector Based Direct Torque Control of Dual Inverter Fed Asymmetrical Six-Phase Induction Motor Drives
Mavila P. C.
;Mohamadian S.;Buccella C.;Cecati C.
2023-01-01
Abstract
A virtual voltage vector based direct torque control (DTC) scheme with enhanced DC bus utilization for an asymmetrical six-phase induction motor (ASPIM) with open-end stator windings is proposed in this paper. In this scheme, the voltage vectors generated by two six-phase, two-level voltage source inverters (VSI) connected to both sides of the stator windings are combined to obtain a virtual voltage (VV) space vector structure in the ASPIM. While generating the virtual voltage vectors it is ensured that the following three conditions prevails in the system: 1) elimination of resultant common mode voltage (CMV) across the stator windings, 2) elimination of triplen order harmonic voltages from the individual 3-phase windings, and 3) nullification of non-torque producing harmonic voltages. Conditions 1 and 2 facilitate the use of a common DC-link for both the VSIs without causing circulation of common mode currents through the stator windings. The third condition obliterates the large, non-torque-producing harmonic currents and consequent losses in the system. The proposed scheme can provide significantly higher DC bus utilization compared to the conventional schemes, for the same DC-link voltage. The effectiveness of the proposed scheme is verified by carrying out simulations using MATLAB-Simulink software, under transient and steady-state operating conditions of the drive.Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
