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This paper presents a control method for a system composed of a photovoltaic (PV) array, five-phase impedance source inverter, five-phase induction motor and centrifugal pump. This method is based on controlling the motor speed to control the pump power as the insolation level or temperature change to attain the maximum power extraction from the PV-array. The motor speed is controlled by using artificial neural network (ANN) which is trained to provide the desired inverter frequency and modulation index at any insolation level and temperature to attain the maximum PV operating power. The data of the neural network are based on the operation of the induction motor at constant air gap flux and perturb and observe method for maximum power point tracking. Simulation results are obtained using MATLAB Simulink to verify the proposed control method. [ABSTRACT FROM AUTHOR]

Power converter faults represent about 12% of electrical system faults. More than 31% of these converter faults are caused by the transistors in the converters. These transistor failures are classified into open-gate and short-gate faults. A fault diagnostic and tolerant control system is proposed in this study for an open-gate fault of a three-phase voltage-source inverter (VSI). The system under study is an induction motor fed by a VSI. The diagnostic technique uses a detection method of positive and negative sequence components, which requires only the measurement of motor currents. The diagnostic signals are derived from the negative sequence components of the motor currents. These signals are then compared using logic functions to trigger the tolerant control. In the case of an open-gate fault, the tolerant system converts the inverter topology from six switches to four switches where the faulty inverter leg is disconnected. The proposed control method was evaluated under steady-state and transient conditions through simulation and experiments. The results confirm an effective and reliable performance of the motor under an open-gate fault. [ABSTRACT FROM AUTHOR]