Comparative study of fuzzy logic speed controller in vector controlled PMSM drive: minimum number of fuzzy rule-base

This paper presents a comparative study on fuzzy rule-base of fuzzy logic speed control with vector-controlled Permanent Magnet Synchronous Motor (PMSM) drive. Fuzzy rule-base design is viewed as control strategy. All fuzzy rules contribute to some degree in obtaining the desired performance. However, some rules tired weakly do not contribute significantly to the final result and can be eliminated. 'Standard design' of fuzzy rule-base of fuzzy logic controller is identified from numerous publications which is 49 rules is used in order to obtain great speed tracking response. It is possible to minimize the complexity of controller's design by reducing number of rule-base from standard 49 rules to 9 rules. Simulation results that verify appropriateness of the approach are included. A comparison of speed response between both designs is studied. Sensitivity of the designs to load disturbance and changes in command settings is studied and also being compared to demonstrate the effectiveness of the reduced rule base

A Fuzzy- Pi - Based Torque Controller For Dtc Of Induction Motor Drives

lt is well established that the implementation of conventional DTC drive consisting of hysteresis-based torque controller suffers from high torque ripple and variation in switching frequency problems. One of the many approaches to tackle this problem is by introducing a non-hysteresis-based torque controller. This paper presents the simulation and analysis of a proposed fuzzy PI-based torque controller for DTC of induction motor drives. Comparisons and analysis between the proposed controller and the hysteresis- and PI -based controllers are presented. The results show that the proposed controller managed to reduce the torque ripple and produce a constant device switching frequency

Analysis Of Multiphase Transformer Supplying A Static And Dynamic Load

Transformers are able to step up or step down an output voltage from their input. It also can be used to directly supply an electrical motor when a constant frequency operation is required. Here, the research is focusing on designing a three-to-five phase transformer that acts as static phase converters for supplying a balance five-phase load. The designing process of the transformer is described based on the graphical phasor diagram that is flexible and easy to be implemented. At the end, the performances of the designed transformer are evaluated using a static and dynamic load. The designed three-to-five phase transformer is able to maintain a balance five phase voltage for several type and level of load as shown in experimental result

Direct Torque Control Of Induction Machine Using 3-Level Neutral Point Clamped Inverter

This paper presents a Direct Torque Control (DTC) of induction motor drives utilizing 3-level neutral-point clamped (NPC) multilevel inverter. This research aims to provide a simple strategy to address capacitor voltage balancing problem of NPC inverter as well as produce better performance for DTC of induction motor in term of reducing torque ripple and high switching frequency. The proposed method uses 2-level hysteresis comparator to restrict the error of upper and lower capacitor voltages and then generate a signal which determine either to increase or decrease the particular capacitor voltage. Using that information, the appropriate selection of small voltage vectors is tabulated in look-up table (LUT) to stabilize the mismatched of capacitor voltage. Simulation results are presented to show the effectiveness of the proposed capacitor voltage balancing strategy

Minimization Of Torque Ripple And Switching Frequency Utilizing Optimal DTC Switching Strategy For Dual-Inverter Supplied Drive

This paper presents an optimal switching strategy employed in direct torque control (DTC) of induction machine utilizing dual-inverter supplied drive. In the proposed switching strategy, the utilization of appropriate amplitude of voltage vectors based on machine operating condition can reduce the rate change of torque slope while improving the performance of DTC drive in term of torque ripple reduction and also minimization of switching frequency variation. This is achieved by modifying the torque error status according to the capability of torque regulation which is done by evaluating the switching frequencies of torque and stator flux error status from the hysteresis comparators. By doing that the suitable amplitude of voltage vectors is able to be applied based on machine operation. All the improvements offered in the proposed strategy are verified through simulation results