Non-independent speed control for dual-PMSM drives fed by a single three-leg VSI

<span>The objective of this article is to analyze the performances of Non-Independent Speed Control of Dual-PMSM (Permanent Magnet Synchronize Motor) Drives by a single Three-Leg Voltage Source Inverter (VSI) using control of Mean and Differential Torque technique. In general, there are two types of control strategies for Dual-Motor drives. One is Master-Slave technique and another one is Mean Control technique. For mean control technique, this study chooses mean and differential approach for the motors parameters and averaging the voltage space vector. The advantages of Dual-Motor drives fed by a single inverter topology are, it can reduce size and cost compared to the Dual-motor drives fed by individual inverter, either in industrial or in traction applications. However, by using a single three-phase inverter, the topology only restricted for the same operating conditions which are at the same speed, same parameters and same direction. The dual-motors are dependent (non-independent) on the other motor. It is can only be tested on different load operation. The analysis is focuses on speed and load variation for Dual-PMSM drives considering the forward and reverse operations of the motor. This simulation model is modelled using MATLAB-Simulink.</span>

Voltage Space Vector Equivalent Substitution Fault-Tolerance Control for Cascaded H-Bridge Multilevel Inverter with Current-Tracking

A novel fault-tolerant control method based on the equivalent substitution of voltage space vector for cascaded H-bridge multilevel inverter with current-tracking is proposed in this paper. With this method, the fault effects on the voltage vector of each sector of the cascaded inverter is analyzed first. Then, an algorithm to substitute the voltage vector in fault state is developed. In the fault state, if the voltage vector selected by the original algorithm cannot be used normally, the redundant voltage vector with the position coincidence is preferentially selected for equivalent substitution. If there is no redundant coincidence vector, select the other vector whose position and effect are closest to it. Compared with the commonly used N + 1 redundancy method, this method does not require the spare cascaded units and can be applied to any class cascaded H-bridge multilevel inverter with current-tracking to improve its reliability. Finally, the effectiveness of the proposed method is validated by simulation and experiment results.