Essam E. M. Mohamed

Flux-Weakening Control of Nonsalient Pole PMSM Having Large Winding Inductance, Accounting for Resistive Voltage Drop and Inverter Nonlinearities

This paper proposes an improved flux-weakening control method to improve the drive performance of nonsalient pole permanent magnet synchronous motors having large winding inductance and consequently an infinite constant power speed ratio. The proposed method consists of two parts. The first part utilizes the voltage differences between the input and output of a minimum-magnitude-error over-modulation block to modify the d-axis current references. The second part uses the compensated q-axis voltage, in which the resistive voltage drop and the distorted voltage due to inverter nonlinearities are taken into account, to detect the maximum torque per voltage (MTPV) line. Under the MTPV condition, a PI controller with a low-pass filter is presented to modify the q-axis current reference. With these two parts, the bus voltage utilization in the proposed method is close to the six-step operation and the actual current trajectory approaches the ideal MTPV line. As a result, the drive performance in the whole flux-weakening region is optimized in terms of maximizing the output torque/power. The method also shows a good performance in transient response. Effectiveness and superiorities of the proposed method are verified by experimental results.

Sliding mode control of linear induction motors using space vector controlled inverter

This paper compares the performance of hysteresis current control and space vector PWM operation of indirect field oriented controlled linear induction motor drive. Sliding mode control or standard PI controllers are applied in the outer control loop to control the mover speed. The inner control loops are standard PI controllers to regulate the direct and quadratic current components. The end effect is taken into account as an external load function of speed in all the studied cases. Numerous simulations are performed based on the MATLAB SIMULINK platform to show the advantages and drawbacks of the system operation based on both controller algorithms and the two modulations techniques.

Comparison of drive performance of PM synchronous machine fed by inverters with different PWM strategies in constant torque and constant power regions

Constant torque and constant power operation performance of permanent-magnet synchronous motors, particularly in the constant power region, not only depends on the flux-weakening control schemes but also relies on the PWM strategies. In this paper, the hysteresis control and SVPWM (including linear and over-modulation) are considered due to their popularity. An improved current regulated delta modulation (CRDM) is developed to improve the performance in both constant torque and constant power regions. The analyses, verified experimentally, show that the improved CRDM strategy demonstrates an improved torque capability which is nearly the same as SVPWM in the constant torque region, and an enlarged speed range compared with hysteresis control.

Field oriented control of sensorless linear induction motor using matrix converter

This paper presents a new controller for the sensorless linear induction motor (LIM) based on field oriented control driven by matrix converter. Conventional PI controlled has been employed for the speed control of mover. Speed estimation of the mover has been employed using Model Reference Adaptive System (MRAS) technique. The PWM switching technique of the matrix converter is designed based on minimum voltage drop switching (MVDS) in order to minimize the converter power loss and harmonic. MVDS switching technique prevents direct switching between minimum and maximum voltage, which reduces the voltage stress on power semiconductor devices. The proposed system has the advantages of high reliability, high efficiency, and low cost due to the elimination of the mechanical speed sensor. The effectiveness of the proposed control technique has been verified using Matlab simulink.

Comparison of Shunt Active Power Filter Control Strategies for Harmonic Compensation in a Paper Industrial Factory

This paper presents the analysis and evaluates different control strategies of shunt active power filters which are used to reduce harmonic distortion created by an industrial paper factory. The model of the whole system has been carried out by Matlab/Simulink. In order to investigate the accuracy of the simulated model, harmonic analysis of simulation results has been compared with measurements from the electrical networks of a Paper Industrial Factory using harmonic analyzer. The consistency of simulation and measured results proves the accuracy of the system modeling. It also proves the validity of using Shunt Active Power Filters to reduce the harmonic distortion in the factory network. Four different control techniques, namely Unit Vector Template Generation, Instantaneous Active and Reactive theory, Synchronous Reference Frame theory and a proposed control strategy that combines the Synchronous Reference Frame and the Unit Vector Template Generation theories, have been studied. Results of each technique were satisfactory and meet the IEEE-519 Standard, However, when the source voltage is distorted the compensation capability for some control strategies is not equal.

Position control of linear induction motor using cascaded sliding mode controller

This paper studies position control of a linear induction motor drive using three cascaded sliding mode controllers. First, the indirect field oriented control of the LIMs is derived, and then cascaded sliding mode controllers design for indirect field oriented control is applied to compensate the uncertainties, which occur with conventional control techniques. The performance of the LIM drive is investigated for cascaded sliding mode controllers of position, speed, and primary current. The effectiveness of the proposed cascaded sliding mode controllers is verified by simulation using MATLAB/SIMULINK software. The performance of the proposed controller is compared with conventional PI-controller at different operating conditions.

Design and analysis of dual Rotor Multi-Tooth Flux Switching machine for wind power generation

This paper aims to design a Double Rotor Multi-Tooth Flux-Switching Generator (DR-FSG) with DC excitation suitable for wind power generation. The proposed design has one stator, two mechanically coupled rotors, and two armature winding groups. Each armature winding group is connected with a bridge rectifier. The outputs from the rectifier circuits are connected in series. The performance of the machine is verified by time stepping finite element analysis (TS-FEA). It is found that, the proposed DR-FSG exhibits good potentials such as reduced torque ripples, flux controllability, and high power density.

Novel salient inner stator Partitioned Stator Switched Flux PM machine

A novel salient inner stator Partitioned Stator Switched Flux PM machine is proposed in this paper. The proposed machine combines the operation principles of the partitioned stators and the outer-rotor switched flux permanent magnet machine. It employs the rotor and stator of a partitioned stator switched flux machine as a rotor and an outer stator respectively and the stator of outer-rotor switched flux PM machine as a salient inner stator. Applying this design, the iron core material of the inner stator can be reduced to half, while the average output torque and electromagnetic performances are not changed. As a consequence the machine is lighter, higher in torque density, and more cost effective.

Maximum Power Point Tracking technique applied on partial shaded grid connected PV system

A PV array is composed of a number of series and parallel modules to meet the voltage, current and power requirements. In this paper, a modified Perturb and Observe (P&O) Maximum Power Point Tracking (MPPT) technique is presented. The modified P&O is used in the maximum power point tracking of a partially shaded PV system. The electrical performance of the proposed partial shaded P&O MPPT technique is compared to the conventional P&O MPPT technique. A MATLAB/SIMULINK model is applied to imitate the PV system under different climate conditions. The results show that the proposed method tracks the MPP efficiently with all levels of shading on the PV array.