Five-Phase Induction Motor

—This paper presents an active phase current harmonic suppression method to smartly and adap-tively perform torque ripple minimization (TRM) under open phase fault conditions in a five-phase permanent magnet assisted synchronous reluctance motor (PMa-SynRM). The five-phase machine is gaining increasing attention due to its promising fault-tolerant and wide speed operation capabilities. However, during fault-tolerant operation, the torque ripple is substantially increased with dangerous vibrations. Until now, most TRM has been primarily performed to maintain constant magneto-motive force (MMF) while only analyzing its fundamental harmonic. However, large torque variations are also caused by unexpectedly modulated high-order harmonic fluctuations which are challenging to predict. This fluctuation in current harmonics is highly destructive to reluctance machines due to its higher nonlin-earity. To address this critical challenge, a real-time active TRM technique has been proposed which will be smartly adaptive to identified harmonic fluctuations. To achieve this, the proposed TRM solution systematically consists of three major steps: (i) active harmonic identification, (ii) harmonic injection, and (iii) vector rotation of phases. To precisely identify fluctuating harmonics in a real-time, a high precision but compact correlation-based monitoring algorithm has been proposed. Detailed theoretical analysis has been carried out through Finite Element Analysis (FEA). The experimental tests are conducted to validate the proposed theory through a five-phase PMa-SynRM drive controlled by TI DSP (F28335).

The paper describes about optimal voltage vector selection for high-performance of Direct Torque Control (DTC) of five-phase induction machine. The decoupled control of stator flux and electromagnetic torque based on hysteresis controllers as employed in conventional DTC is applied to retain the simplicity and to provide quick instantaneous control. A look-up table that selects the most optimal voltage vectors according to the speed operations, i.e. low-speed, middle-speed and high-speed is proposed to improve DTC performances such as excellent torque dynamic control, minimization of torque ripple, high-efficiency (due to lower switching frequency) and extension of constant torque region. All the improvements are validated through simulation results.

This paper describes a study of Switching Table Direct Torque Control (ST-DTC) and Fuzzy Rule based Direct Torque Control (FR-DTC) in case of a three phase induction motor. The hysteresis band and the switching table used in the ST-DTC scheme have been replaced by a Fuzzy Rule based controller in the FR-DTC. Results show that the FR-DTC method provides better transient performance compared to the ST-DTC method.

The first generation of multi-machine systems is limited on two .the first configuration consists of a continuous floor which feeds several three-phase inverters connected in parallel, or each inverter supplies a three-phase machine .the control of each machine is independent via its inverter and its algorithm control .the second configuration consists of a single inverter, which also feeds in parallel three phase machines .for this structure, the machines must have the same speed and suffer the same torque load .these two conditions make the use of this system in a limited scope .It is impossible to connect in series several three-phase machines powered by a single-phase power converter and that each machine in the group have an independent speed control .but, the use of multi-phase converters associated with polyphase machine. generate additional degrees of freedom .With these, several polyphase machines can be connected in series in an appropriate transposition phases. The objective of this work is to order, model and characterize the behavior of a training system multimachines composed of two five phase synchronous permanent magnet motors connected in series and powered by a five phase matrix converter applied to the rail traction.

Soft Multi agent controllers are used for control of complex systems. Induction motor is widely used in industrial applications. But due to its highly non linear behavior its control is very complex. Non linear speed control techniques are employed to improve dynamic performance of electric drives. Paper describes multi agent based approach to control speed of Induction motor. Design and simulation of Multi Agent System is developed for Indirect vector controlled 3-phase Induction motor. Soft computing techniques are used for implementation. Three types of controllers: Classical controller (PI), Fuzzy (FLC) & Neural Network ANN) are constitutant of the Multi Agent system. Simulated speed responses parameters viz: rise time, steady state error and overshoot of SIMULINK models are used to make by a fuzzy logic is used to select the best controller from the constituents.

The fore most issue in DTC based induction motor drive is its torque ripples. The core objective of this paper is to reduce the electromagnetic torque ripples by varying the hysteresis controller bandwidth. Space Vector Modulation (SVM) based Direct Torque Controlled (DTC) induction motor drive is simulated in MATLAB/SIMULINK environment and its performance is studied with step change in load torque. The influence of hysteresis controller bandwidth on the performance of induction motor drive is analysed in terms of stator flux and electromagnetic torque ripples. The electromagnetic torque response and the stator flux trajectory for different values of hysteresis controller bandwidth are obtained and the results are presented.

In this paper, the control of five-phase induction machine using Direct Torque Control (DTC) is presented. The general D-Q model of five-phase induction machine is discussed. The de-coupled control of stator flux and electromagnetic torque based on hysteresis controller similar to conventional DTC is applied to maintain the simplicity of the system. Three sets of lookup tables consist of voltage vectors with different amplitude that selects the most optimal voltage vectors according motor operation condition is proposed. This provides excellent torque dynamic control, reduces torque ripple, lower switching frequency (high efficiency) and extension of constant torque. Simulation results validate the improvement achieved.