A new approach to three-phase asynchronous motor model for electric power system analysis

In this paper, a new steady-state model of a three-phase asynchronous motor is proposed to be used in the studies of electrical power systems. The model allows for obtaining the response of the demand for active and reactive power as a function of voltage and frequency. The contribution of the model is the integration of the characteristics of the mechanical load that can drive motors, either constant or variable load. The model was evaluated on a 2500 kW and 6000 V motor, for the two types of mechanical load, in a wide range of voltage and frequency, as well as four load factors. As a result of the evaluation, it was possible to verify that, for the nominal frequency and voltage variation, the type of load does not influence the behavior of the powers and that the reactive power is very sensitive to the voltage variation. In the nominal voltage and frequency deviation scenario, it was found that the type of load influences the behavior of the active and reactive power, especially in the variable load. The results demonstrate the importance of considering the model proposed in the simulation software of electrical power systems.

A novel direct torque and flux control of permanent magnet synchronous motor with analytically-tuned PI controllers

<span lang="EN-US">This work presents a novel direct torque and flux control (DTFC) of permanent magnet synchronous motor (PMSM) with analytically-tuned proportional integral (PI) controllers. The proportional (K_p) and integral (K_i) gains of the PI controllers were accurately determined, from first principle, using the model of the control system. The PI flux and torque controllers were then developed in rotor reference frame. The designed PI controllers, together with the torque and flux controllers, were tested on a permanent magnet synchronous motor (PMSM). The results obtained were compared with results from conventional DTFC system using manually-tuned PI controllers. The total harmonic distortion (THD) of motor phase currents is 18.80% and 4.81% for the conventional and proposed models respectively. This confirms a significant reduction in torque ripples. The control system was tested for step torque loading and found to offer excellent performance both during load changes, speed reversal, and constant load conditions.</span>

Intensifications reactive power during of asymmetric network outages in dual-stator winding generators

<span lang="EN-US">The paper proposes a protection to dual stator generator, reluctance rotor, from asymmetrical fault. Which prevents the dual stator generator, reluctance rotor, from electrical sage through working process in order to avoid any interruption in the generator-grid connection. The procedure consummated with injecting suitable reactive power during the fault period. The proposed method that makes it possible for wind turbine application via dual stator winding generators (DSWRG) synchronous mod to stay connected to the grid during asymmetrical faults. It has been built according to trusted simulating mode considering all tested parameters according to experiment work. The expirment, consider the DC link side stability and care about the behavior and performance of machine side parameter. As well the machineability is evaluated to ride through asymmetrical fault by observing the secondary side current which has a big role in saving grid side converter. The control takes a response within 200 ms after fault trigger recognition. The generator ability of dynamically remaining connected stable and existing in the network, which is sustained a series voltage disturbance by injecting appropriate amount of reactive power. The main interest required in this paper is the capability of a machine to overcome the asymmetrical fault.</span>

Performance analysis of brushless DC motor with optimum magnetic energy for bicycle application

<span lang="EN-US">Brushless DC (BLDC) motor is widely used for various applications such as transportation. BLDC motor has many advantages compared to brush motor such as more compact, high robustness and simplest construction. The maintenance of this motor also low compared to brush motor due to absent of the brush inside the motor. For electric bicycle application, the conventional motor has low electromagnetic torque because not properly designed. It faces low torque density as the motor in full load condition especially during climb uphill. In this research, an optimum magnetic energy is being determine by proper selection of permanent magnet size. In addition, this research also increases the input current in dynamic condition into the designed BLDC motor. Finite element method (FEM) is used to analyze other performance characteristic of improved motor such as back electromotive force (EMF), electromagnetic torque, flux linkage, and stator flux density. Parameter for improve the current motor are selected and varied based on the required specification. In conclusion, the research proposed the new motor specification that has highest electromagnetic torque of brushless DC motor. Finally, this research provides guidelines, suggestions and proposes a better improved structure in optimize the magnetic energy in BLDC motor.</span>

Design of new structure of multilevel inverter based on modified absolute sinusoidal PWM technique

The advantage of multilevel inverters is to produce high output voltage values with distortion as minimum as possible. To reduce total harmonic distortion (THD) and get an output voltage with different step levels using less power electronics switching devices, 15-level inverter is designed in this paper. Single-phase 11-switches with zero-level (ZL) and none-zero-level (NZL) inverter based on modified absolute sinusoidal pulse width modulation (MASPWM) technique is designed, modelled and built by MATLAB/Simulink. Simulation results explained that, multilevel inverter with NZL gives distortion percent less than that with ZL voltage. The THD of the inverter output voltage and current of ZL are 4% and 1%, while with NZL is 3.6% and 0.84%, respectively. These results explain the effectiveness of the suggested power circuit and MASPWM controller to get the required voltage with low THD.

Small-signal analysis of a single-stage bridgeless boost half-bridge AC/DC converter with bidirectional switch

A small-signal analysis of a single-stage bridgeless boost half-bridge alternating current/direct current (AC/DC) Converter with bidirectional switches is performed using circuit averaging method. The comprehensive approach to develop the small signal model from the steady state analysis is discussed. The small-signal model is then simulated with MATLAB Simulink. The small-signal model is verified through the comparison of the bode-plot obtained from MATLAB Simulink and the simulated large signal model in piecewise linear electrical circuit simulation (PLECS). The mathematical model obtain from the small-signal analysis is then used to determine the proportional gain K_p and integral gain K_i. In addition, the switch large-signal model is developed by considering the current and voltage waveforms during load transients and steady-state conditions.

Improved filtering H∞ finite frequency of Takagi-Sugeno fuzzy systems

The work treats the filter H∞ finite frequency (FF) in Takagi-Sugeno (T-S) two dimensional (2-D) systems described by Fornasini-Marchesini local state-space (FM LSS)models. The goal of this work is to find an FF H∞ T-S fuzzy filter model design in such a way that the error system is stable and has a reduced FF H∞ performance over FF area swith noise is established as aprerequisite. Via the use of the generalized Kalman Yakubovich Popov (gKYP) lemma, Lyapunov functions approach, Finsler’s lemma, and parameterize slack matrices, new design conditions guaranteeing the FF H∞ T-S fuzzy filter method of FM LSS models are developed by solving linear matrix inequalities (LMIs). At last, the simulation results are provided to show the effectiveness and the validity of the proposed FF T-S fuzzy of FM LSS models strategy by a practical application has been made.

Least mean sixth control approach for three-phase three-wire grid-integrated PV system

<p><span lang="EN-US">This work proposes an adaptive filter based on a new least mean sixth control approach with incremental conductance method of MPP for 3-phase grid-incorporated photovoltaic (PV) system. The proposed system comprises a PV array, 3-phase DC to AC converter, maximum power point tracker (MPPT), three-phase electronic load, and a 3-phase grid. The combination of solar PV array and the voltage source converter (VSC) supplies power to the grid. The 3-phase inverter as a distribution static synchronous compensator (D-STATCOM) improves the quality of the system performance in case of zero solar irradiation. D-STATCOM also reduces total harmonic distortion (THD) in grid currents, improves power factor, and maintainsa constant voltage at the point of common coupling (PCC). The system modelling and simulation is achieved on MATLAB/Simulink. The proposed system performance has been found satisfactory and conform to IEEE-519 standards.</span></p>

Performances analysis of interior permanent magnet motors having different rotor iron pole shapes

<p><span lang="EN-US">Interior permanent magnet motors (IPMMs) have been increasing in popularity, since the emergence of permanent magnet material with high energy products, i.e. rare earth permanent magnet material. This paper analyses the performances of IPMMs having different rotor iron pole shapes including eccentric, sinusoidal and sinusoidal with 3th order harmonic injected rotor pole arc shapes IPMMs. Cogging torque, static torque, torque ripple, torque-speed and power-speed curves of the mentioned motors have been compared. It must be noted that the mentioned motors have been designed with the same stator, PM shape and the same dimensions, in order to highlight the effect of the rotor pole arc shape on the performance of the such motors. Two-dimensional (2D) finite element analysis (FEA) has been utilized to design and analyze the mentioned machines. It has been found that rotor iron pole shape of the IPM has notably influence on the machine performance, practically on output electromagnetic torque and its ripple. The highest value of average electromagnetic torque as well as torque capability in the constant torque reign is delivered by 3th order harmonic injected rotor pole arc shapes machine, while the lowest torque ripple is obtained by the sinusoidal rotor pole arc machine.</span></p>

Load frequency control of thermal system under deregulated environment using slime mould algorithm

This paper emphasizes the significance of PID controller parameters using a slime mould algorithm (SMA) to reduce load frequency control (LFC) issues in a thermal system in an open market scenario. The SMA is used to solve the parameterization of the PID controller, which was formulated as an optimization problem.The performance of the PID controller parameters improves the dynamic characteristics of the system as frequency in each area, and also deviations in tie line power after sudden load violation. In order to study the efficiency of the proposed method, the system was tested with different power transactions for a small load disturbance and the comparative results were presented. The optimal value of the controller parameters derived from SMA based PID controller is estimated using a finite nonlinear optimization using a performance index based method.