Three level fault tolerant DTC control for induction machine drives

Improved switching‐table‐based DTC strategy for the post‐fault three‐level NPC inverter‐fed induction motor drives

“…In the ST of this DTC strategy [17], the proper basic voltage vector is selected according to the error of flux and torque. According to previous analysis, the U c1 and U c2 will be in a serious imbalance by using the conventional ST-DTC strategy without the control algorithm of the dc-link capacitor voltages.…”

“…For the traditional DTC strategy of the ESTPI‐fed induction motor drives, only two hysteresis comparators are adopted to regulate the stator flux and the electromagnetic torque, respectively, and the imbalance of U c1 and U c2 and the torque ripple are not considered. In the ST of this DTC strategy [17], the proper basic voltage vector is selected according to the error of flux and torque. According to previous analysis, the U c1 and U c2 will be in a serious imbalance by using the conventional ST‐DTC strategy without the control algorithm of the dc‐link capacitor voltages.…”

“…Therefore, the topology called eight-switch three-phase inverter (ESTPI) presented in Fig. 1a [9] is a promising option as the post-fault reconfigured topology of the 3L-NPC inverter under the open-circuit fault occurring in a leg, and it has attracted more and more attention in recent years [9][10][11][12][13][14][15][16][17]. At present, several pulse-width modulation (PWM) methods for the ESTPI have been proposed [9][10][11][12][13][14].…”

“…Due to the advantages of simple control structure, fast dynamic response, and no need for complex coordinate transformation, the DTC strategy has been widely applied in various areas [18][19][20][21][22][23]. Currently, the above-mentioned two classical control strategies have been extended to the ESTPI-fed induction motor drive systems [15][16][17]. Among them, the performance analysis of SVPWM-based FOC strategies for ESTPI-fed induction motor drives has been presented in [15].…”

“…The motor temperature, iron losses and the global efficiency under inverter normal and post‐fault reconfiguration operations have also been discussed by using the FOC strategy [16]. In [17], a switching table‐based DTC strategy was proposed for the ESTPI‐fed induction motor drives. However, these control strategies do not take the dc‐link capacitor voltages imbalance into account.…”