Indirect Field Research Articles

Operation and Testing of Indirect Field Oriented Control of Asymmetrical Six-Phase Open-Ended Winding Induction Machine Using Hardware-in-Loop (HIL) Emulator

This study deals with an asymmetrical six-phase open-ended winding induction machine in closed loop operation using indirect field-oriented control scheme. The closed loop scheme has been developed by using the two axis (d-q) modeling of six-phase induction machine in rotating synchronous reference frame and can be easily extended to any multiphase machine having the stator winding which are the multiple of three. Operation under steady-state is considered to develop the phasor diagram in closed loop operation of machine in the motoring mode. The performance of the asymmetrical six-phase induction machine (opened ended winding) is investigated in the entire four-quadrant operation. The complete machine drive system was developed by using MATLAB/Simulink, which was used to obtain analytical results in different modes. Furthermore, the analytical results in the motoring mode were experimentally validated through real-time simulation by using Typhoon hardware-in-loop (HIL) emulator.

A combined HT and ANN based early broken bar fault diagnosis approach for IFOC fed induction motor drive

In recent years, fault diagnosis in the Induction Motor Drive (IMD) has been a popular and important field in the motor-drive research area. The development of control circuits for induction motors has prompted the attention of both researchers and industrialists. This paper proposes a broken bar fault diagnosis using Hilbert Transform (HT) and Artificial Neural Networks (ANN), with the drive regulated through the Indirect Field Orientation Control (IFOC). The HT obtains the spectrum of stator current, which is utilized to identify the Broken Rotor Bar (BRB) failure. The magnitude and side-band frequency of the drive are extracted using the Fast Fourier Transform (FFT), and these parameters are fed into the ANN inputs. The fault severity is computed by the ratio of mean side-band frequency amplitude to the main frequency amplitude for finding the impact of failure in the drive. ANN is used to diagnose failure with high accuracy. The tested and training results are used to attain the minimum Mean Square Errors (MSEs). The IFOC is involved in this proposed system to ensure high performance under the variable speed drives. The proposed scheme is validated in both MATLAB/Simulink and experimental platforms.

Dual Three Phase Multilevel Space Vector Modulation Control of Diode Clamped Inverter for Dual Star Induction Motor Drive

This work suggests a dual three-phase Space Vector Modulation (SVM) for the Diode Clamped Multilevel Inverter (DCMI) to ensure a robust control of Dual Star Induction Motor (DSIM). The principal scheme is investigated to apply the same control of the six-phase multilevel inverter by two three-phase multilevel inverter to drive the DSIM. The use of classic SVM control offers significant simplifications for controlling a six phase five levels inverter. The proposed control approach employs according to the hybridization of various conversion functions to establish the modulation strategy for each voltage vector and its placement in the plane of voltage modulation in distinctly and easy manner. A numerical simulation under MATLAB/Simulink is carried out to evaluate the Indirect Field Oriented Control (IFOC) of DSIM drive fed by multilevel inverters. The simulation outcomes clearly reveal good performance of the designed control strategy in terms of THD and control efficiency.

Evaluating the performances of PI controller (2DOF) under linear and nonlinear operations of DFIG-based WECS: A simulation study

Owing to different stochastic characteristics of wind energy systems, there would commonly be uncertainties in the processes of wind energy conversion that may ultimately cause to severely degrade the quality of electric power production. These uncertainties include time-varying fluctuations of mechanical & electrical parameters that can be generated during both linear, and nonlinear operating behaviors of doubly fed induction generator-based wind energy conversion system (DFIG WECS). In order to handle a wind power quality problem, the previous studies largely focused on adjustment of mechanical parameters particularly based on blade pitch angle control by proposing different control strategies, and controller models. This work proposes a rarely studied electrical parameter control method that is particularly used to implement the regulation of rotor current components & electromagnetic torque in a DFIG WECS, based on Indirect Field Oriented Control (IFOC) strategy. Accordingly, a novel Proportional Integral controller model that employs a 2-Degree-of-Freedom [PI (2DOF)] is illustrated for an enhanced control of the rotor current components (quadrature & direct currents), electromagnetic torque under a 2MW DFIG WECS, which is operationally assumed to behave both linearly & nonlinearly. Herein, nonlinear operating behavior signifies a voltage dip that was assumed to be resulting when the system's normal (linear) voltage would suddenly drop by 90%. Furthermore, the overall model of the DFIG system was simulated in MATLAB-SIMULINK environment to evaluate the performances of PI controller (2DOF) under the system's stated operating behaviors. Based on the simulation signal statistics, the quadrature current distortion levels & DC mean values were mainly considered as the criteria for evaluating the controller performances. Finally, the proposed PI controller (2DOF) model has been tested to achieve an enhanced power quality in comparison with the traditional PI controller model.

An Adaptive Control of Electric Vehicle Based on Nine Switches Inverter Fed Two Induction Motors

This paper deals with an adaptive control of two driving-wheels electric vehicle. Indeed, an Indirect Field Oriented Control of two induction motors fed simultaneously by Nine Switches Inverter has been included. Hence, to ensure an independent control of the two induction motors, a specified Space Vector Pulse Width Modulation strategy for Nine Switches Inverter is developed. For this, a switching table and a switch-over bloc are proposed. The effectiveness of the proposed control strategy is evaluated and validated by simulations and experimental tests. In this context, the developed system can be used as a promising solution for an independent control of two driving wheels of electric vehicle using a software differential.

Moderate resolution LAI prediction using Sentinel-2 satellite data and indirect field measurements in Sikkim Himalaya.

The leaf area index (LAI) has been traditionally used as a photosynthetic variable. LAI plays an essential role in forest cover monitoring and has been identified as one of the important climate variables. However, due to challenges in field sampling, complex topography, and availability of cloud-free optical satellite data, LAI assessment on larger scale is still unexplored in the Sikkim Himalayan area. We used two optical instruments, digital hemispherical photography (DHP) and LAI-2200C, to assess the LAI across four different forests following 20 × 20m2 elementary sampling units (ESUs) in the Himalayan state of Sikkim, India. The use of Sentinel-2 derived vegetation indices (VIs) demonstrated a better correlation with the DHP based LAI estimates than using LAI-2200C. Further, the combination of both reflectance bands and VIs were integrated to predict the LAI maps using random forest model. The temperate evergreen forests demonstrated the highest LAI value, while the predicted maps exhibited LAI maxima of 3.4. The estimated vs predicted LAI for DHP and LAI-2200C based estimation demonstrated reasonably good (R2 = 0.63 and R2 = 0.68, respectively) agreement. Further, improvements on the LAI prediction can be attempted by minimizing errors from the inherent field protocols, optimizing the density of field measurements, and representing heterogeneity. The recent rise of frequent forest fires in Sikkim Himalaya prompts for better understanding of fuel load in terms of surface fuel or canopy fuel that can be linked to LAI. The high-resolution LAI map could serve as input to forest fuel bed characterization, especially in seasonal forests with significant variations in green leaves and litter, thereby offering inputs for forest management in changing climate.

Improvement of Sliding Mode Control Strategy Founded on Cascaded Doubly Fed Induction Generator Powered by a Matrix Converter

The current paper presents a Sliding Mode Controller (SMC) for indirect field-oriented Cascaded Doubly Fed Induction Generator (CDFIG) powered through a Matrix Converter (MC). The proposed SMC employs a continuous control strategy to accomplish free chattering fractional-order sliding-mode control and to ensure that the control of the first DFIG stator's reactive and active power is separated. An MC is used to control the current provided to the second stator of the CDFIG as an alternative to standard voltage source inverters. The two MCs are controlled via Space-Vector Pulse-Width Modulation (SVPWM) and Indirect Field Oriented Control (IFOC). The proposed Wind Power Generation System (WPGS) is used with the purpose to ensure Maximum Power Point Tracking (MPPT) sensing under various disturbance variables such as turbulent wind. The simulation results prove the efficiency and robustness of the proposed method.

Dynamic Modeling and Control of Pole-Phase Modulation-Based Multiphase Induction Motor Drives

Pole-phase modulation based multiphase induction motor (PPMIM) drives possess the capability of providing an extended range of speed-torque for high power traction application with the available additional degrees of freedom in the multiphase machine. As observed in previous open-loop results of PPMIM drives presented in the literature, the transient currents often exceed twice the rated currents. To address this issue, this paper focuses on the modelling and advanced control of the PPMIM drives during all possible pole-phase combinations. The dynamic mathematical modelling of the PPMIM in actual phase variable domain is presented in detail. Since this model involves time-dependent inductances and torque, the machine model equations are transformed into dq domain using transformation matrices. The transformation matrices, modelling equations in the arbitrary reference frame and multiphase inverter are modelled by considering all parameters of possible pole-phase combinations. Based on the proposed modelling equations, an indirect field oriented control (IFOC) is implemented for PPMIM drives for smoother operation in all possible modes of operation. The modelling equations, as well as IFOC of PPMIM drive, are implemented in MATLAB to illustrate the behaviour of machine during transients as well as different load torques. The proposed concepts are also validated on laboratory setup and the hardware results are demonstrating the smoother transition as well as steady state operation of PPMIM drive in pole changeovers as well as both pole-phase combinations.

Implementasi Pendekatan Saintifik di Lembaga Pendidikan Anak Usia Dini

The scientific approach is a learning process that is designed in such a way, so that in the learning process students can actively participate. There are five stages in the scientific approach, namely observing, asking questions, gathering information, processing information, and communicating. This study uses qualitative research with direct and indirect field observations in several private kindergartens in Keruak District. Data collection techniques in this study include observation, interviews and documentation. The results of this study indicate that (1) In observing activities, students are expected to be able to ask questions about information that has not been understood even though the language is quite limited due to language skills that are still limited. (2) Children can collect information from activities carried out by students as well as simple experiments with the guidance and direction of educators. (3) Students are stimulated to be able to think logically and systematically to obtain conclusions in the form of knowledge. (4) Students can communicate what students get from the observations they have made. (5) Scientific learning is able to stimulate children's creativity because children are more independent, confident, dare to have opinions, and have high curiosity.

Parameter Tuning of Sliding Mode Speed Controller of Induction Motor Drive Using Teaching-Learning Based Optimization Algorithm

The optimal settings of the Sliding Mode Controller for three-phase Induction Motor speed regulation are proposed in this paper using a Teaching-Learning Based Optimization Algorithm. It is a straightforward metaheuristic algorithm that simulates the teaching-learning processes in a classroom. Indirect Field Oriented Control is used in this induction motor drive, which allows the motor torque and the flux to be separated, similar to a DC motor. The inner loop uses proportional-integral current controllers, whereas the outside loop uses a sliding mode speed controller. In this paper, the sliding mode controller uses a tanh function as a switching function. Integral Time Absolute Error and Zwe-Lee Gaing's parameters are used as objective functions for tuning sliding mode controller settings. Performances of the proposed scheme in terms of the transient response analysis are compared with the swarm intelligence-based algorithms, namely the modified Particle Swarm Optimization and Grey Wolf Optimization. MATLAB/ SIMULINK software is used to build the three algorithms and sliding mode controller-based induction motor drive models, which are then analysed using simulation experiments. In comparison to the modified Particle Swarm Optimization and the Grey Wolf Optimization algorithms, Teaching-Learning Based Optimization yields the lowest value of the objective function Zwe-Lee Gaing's parameter and it converges quickly.

Chattering Reduction Using Boundary-SMC on Low-Speed Setting of 3-Phase Induction Motor with IFOC Method

Vector control has been widely used in induction motor speed settings due to its high performance and ability to be separately controlled as DC motors. Indirect Field Oriented Control (IFOC) is a vector control method applicable to induction motors due to the ease of design and implementation. However, its performance decreases due to changes in motor parameter variations and load disturbances, which led to the use of Sliding Mode Control (SMC), capable of resisting and stabilizing parameter changes and load disturbances. In the First Order Sliding Mode Control (FOSMC), a dangerous chattering phenomenon occurs and results in the stability of the control system. Therefore, this research designed a Boundary-SMC controller to control the speed of a 3-phase induction based on IFOC with a change in load disturbance to reduce the chattering phenomenon at low speeds, where the largest percentage occurs. Furthermore, this research used Lyapunov's stability theory to ensure stability with the performance of these controls monitored and analyzed in LabView. The results showed that FOSMC has better resilience and stability than PID, with a steady error rate of 0.001% and a chattering percentage of 0.12%. With Boundary-SMC, the chattering percentage and stiffness are reduced to 0.005% and 0.284%, respectively.

An Enhanced Sliding Mode Speed Control for Induction Motor Drives

In this paper, an enhanced Integral Sliding Mode Control (ISMC) for mechanical speed of an Induction Motor (IM) is presented and experimentally validated. The design of the proposed controller has been done in the d-q synchronous reference frame and indirect Field Oriented Control (FOC). Global asymptotic speed tracking in the presence of model uncertainties and load torque variations has been guaranteed by using an enhanced ISMC surface. Moreover, this controller provides a faster speed convergence rate compared to the conventional ISMC and the Proportional Integral methods, and it eliminates the steady-state error. Furthermore, the chattering phenomenon is reduced by using a switching sigmoid function. The stability of the proposed controller under parameter uncertainties and load disturbances has been provided by using the Lyapunov stability theory. Finally, the performance of this control method is verified through numerical simulations and experimental tests, getting fast dynamics and good robustness for IM drives.

Grid integration of doubly-fed induction machine using indirect field oriented control

Renewable energy resources technologies such as wind power-based generators are being classified under the segment of emerging advancements in the domain of power generation. The following research showcases the experimental analysis and simulation of the Doubly-Fed Induction machine (DFIM) implemented in the wind energy generation systems using MATLAB Simulink. The experimental and simulation outcomes represent the implementation and control, steady state analysis, integration with the wind turbines and grid convertor implementation with respect to wind turbines based on DFIM.

Optimization for a Photovoltaic Pumping System Using Indirect Field Oriented Control of Induction Motor

Due to the increase in electricity and diesel costs, solar photovoltaic pumping systems have become a good solution, especially in rural areas. This work presents a standalone photovoltaic (PV) water pumping system (PVWPS) driven by an induction motor without energy storage to improve the pumping system’s performance. First, a comparison is made between two types: perturb and observe (P&O) method and incremental conductance (INC) MPPT method with a variable step size that is automatically adjusted. Studying these two techniques helps to understand which one can result in a system with less oscillation and greater efficiency when tracking the maximum power point from the PV panel under sudden irradiation conditions. This MPPT works on the operating duty cycle of the boost converter. Then, that converter combines with a voltage source inverter (VSI) to convert DC power to AC power. Second, we use indirect field-oriented control (IRFOC), which drives the three-phase of an induction motor in turn to run the centrifugal pump. The simulation results of this work were obtained using the MATLAB Simulink platform.

Students’ Reactions to Virtual Geological Field Trip to Baengnyeong Island, South Korea

In this study, we evaluated affective components of the learning processes of students after being exposed to a virtual geology field trip of the Baengnyeong Island, South Korea. Changes in students’ cognition of and interest in science and scientific attitude were measured before and after exposure to the virtual field trip. We exposed 106 middle school students to the program and our results revealed that this program had a positive impact on their scientific attitude (p value = 0.014) but no significant changes were observed in the students’ cognition of and interest in science (p value = 0.166). The significant finding from this study was that the VFT program can bring positive scientific attitude as a component of affective learning process. The affective learning process influences the cognitive learning processes and eventually the academic achievement of the students can be improved. In the students’ satisfaction survey, the highest satisfaction level was in the convenience of the program. As access to Baengnyeong Island is limited, though the island is an ideal location for studying geological phenomena, the VFT can be a useful tool for instilling a positive scientific attitude in students via indirect field experience. It can be a good alternative to bridge the education gap between students with special needs who are less mobile and other students.

Speed Control with Indirect Field Orientation for Low Power Three-Phase Induction Machine with Squirrel Cage Rotor

Induction machines are widely used in the industry due to their many advantages compared to other industrial machines. This article presents the study and implementation of speed control applied to a Three-phase Induction Machine (MIT) of the squirrel cage type. The induction motor was modeled using the rotor flux in the synchronous reference to design Proportional-Integral (PI) type controllers for the current and velocity control loops. It is the objective of the article also to present in detail the development of converter hardware that comprises the stages of power, acquisition, and conditioning of engine signals. The system was simulated using computational tools and validated using a prototype designed, constructed, and commissioned.

High gain boost converter fed asynchronous motor drive for water pumping system

ABSTRACT High gain dc–dc boost chopper are rapidly expanding substituting power converters for Photo Voltaic (PV) appliances. Investigators are creating different schemes to accomplish greater voltage gain, low ripple, switch stress, decreases the cost of converters and reduces the fluctuations at the photovoltaic operation point. This paper proposes a two-stage converter for standalone solar photovoltaic (PV) water pumping drive system. High Gain (HG) cell combined with DC-to-DC boost converter. This compound converter provides dc voltage fed asynchronous motor drive system. The utilisation of three-phase asynchronous motor introduces a superior solution to the industrial DC motor-based water pumping scheme. A three-phase asynchronous motor connected to voltage source inverter (VSI), which in turning throws the centrifugal pump. The scheme comprises of a PV array, high-gain DC–DC chopper, 3-Phase Voltage Source Inverter (VSI), motor and a pump. Incremental conductance method used to obtain maximum power from a solar PV structure. Indirect Field Oriented Control of an asynchronous motor is employed to achieve soft starting of the motor. The scheme setup is simulated using MATLAB/Simulink. The proposed system is tested experimentally. The results accomplished demonstrate the scheme fitness for PV water pumping.

Fixed-Time Synergetic Control-Based Chaos Suppression for Eighth-Order IFOCIM Drive System

This paper investigates chaos suppression in widely used indirect field oriented controlled induction machine (IFOCIM) drive system using fixed-time synergetic control method. The complex eighth-order IFOCIM drive system shows chaotic oscillations during a specific range of the integral gain of the PI speed controller. The conventional synergetic control method is improved by employing the fixed-time theory, the characteristics of the designed controller are chattering free and the convergence time is limited within a fixed-time upper bound depending on the controller parameters. The fixed-time synergetic control method is used to converge a selected macro variable to the origin within the fixed time upper bound. The controller can stabilize the chaotic system dynamics in a good way within a short time.

ROBUST DIRECT FIELD ORIENTED CONTROL OF INDUCTION GENERATOR

A novel and robust field oriented vector control method for standalone induction generators (IG) is presented. The proposed controller exploits the concept of direct field orientation and provides asymptotic rotor flux modulus and DC-link voltage regulations when a DC-load is constant or slowly varying. Flux subsystem, designed using Lyapunov’s second method, has, in contrast to standard structures, closed loop properties and therefore is robust with respect to rotor resistance variations. A decomposition approach on the base of the two-time scale separation of the voltage and torque current dynamics is used for design of the voltage subsystem. The feedback linearizing voltage controller is designed using a steady state IG power balance equation. The resulting quasi-linear dynamics of the voltage control loop allows use of simple controllers tuning procedure and provides an improved dynamic performance for variable speed and flux operation. Results of a comparative experimental study with standard indirect field oriented control are presented. In contrast to existing solutions, the designed controller provides system performances stabilization when speed and flux are varying. It is experimentally shown that a robust field oriented controller ensures robust flux regulation and robust stabilization of the torque current dynamics leading to improved energy efficiency of the electromechanical conversion process. The proposed controller is suitable for energy generation systems with variable speed operation. References 18, figures 8.

PSO based controlled six-phase grid connected induction generator for wind energy generation

This paper deals a detailed performance investigation of asymmetrical six-phase grid connected induction generator (GCIG) in two proposed configurations in variable speed operation. During the system development, regulation of DC-link voltage has been proposed using particle swarm optimization (PSO) based PI controller, ensuring the power flow to utility grid through back to back converters. The closed loop operation of asymmetrical six-phase GCIG using indirect field oriented control in different configurations has been carried out in Matlab/Simulink environment. Analytical results have been verified using real time test results on virtual platform of Typhoon HIL supported with some experimental validation.