Field Oriented Control Technique Research Articles

Tuning of modern speed drives using IFOC: A case study for a five-phase induction machine

Electric machines have existed since the beginning of the 19th century. Although variable-speed drive technology has evolved considerably during the last years, the indirect field-oriented control technique has been in use as a standard control method since the 1960s, using an outer speed loop and an inner current loop. This paper deals with the non-trivial problem of tuning the outer speed controller of modern variable-speed drives, where experimental results are provided to show the need for new tuning methods. The influence of non-modeled effects on the performance of the drive is illustrated considering the dynamical effect of the mechanical speed sensing procedure using optical devices. This effect has not been generally considered. However, it is shown that it has a notable effect on tuning for high performance drives. This is especially true when considering some figures of merits of relevance for drives, such as the torque ripple. A Pareto analysis is proposed to reveal trade-offs between typical figures of merit to establish new tuning methods. To focus our contribution, a five-phase induction drive is considered as the case study, using a finite-state model predictive controller for the stator current control and PI regulators for the outer speed control loop.

Speed Measurement Delay and its Influence on IFOC Tuning

The Indirect Field-Oriented Control technique has been in use since the 1960s, with some innovations added to the basic original setting. Although variable-speed drive technology has evolved considerably, basic assumptions remain in place. This paper deals with the problem of sensing the mechanical speed using optical devices. This aspect has not been considered in previous works. To focus the contribution, finite-state model predictive control is used in this paper for stator current control. The outer (speed) loop considers PI control as is usually the case. The experimental results presented here show the need for new tuning methods.

Control and Performance Analysis of an Indirect Matrix Converter Fed Triple Star Induction Motor

Efficient operation is a recommended factor in most of industrial applications. In this paper, an indirect matrix converter (IMC) topology is developed and proposed to substitute the classical (AC/DC/AC) three phase converter topologies; where the control strategy is frequently performed with a voltage source inverter (VSI). Large electrolytic capacitors are viewed as hazardous due to their short lifetime compared to ordinary capacitors and power switches, as well as their contribution to the total bulk and weight of the converter. Matrix converters may be the answer to getting rid of the capacitor, shrinking the converter, and improving its efficiency (MC). These advantages are offset by the fact that the (MC) calls for a tricky switching technique based on pulse width modulation, which is prone to commutation failure. The direct frequency conversion using the indirect matrix converter (IMC) with many advantages has appeared as an alternative to these conventional voltage inverters. This study investigates a field-oriented control (FOC) scheme for indirect matrix converter fed triple star induction motor (TSIM). After building the proposed IMC converter topology, an adequate field-oriented control strategy-based space vector modulation (SVM) is proposed and adapted for the control of the triple star induction motor. The FOC technique guarantees flux and torque decoupling while ensuring good operation performance as required in many industrial applications. The obtained numerical simulation results show and confirm the effectiveness of this control scheme.

Field oriented control technique applied to the PMSM without mechanical sensor, based on the cubature KALMAN filter observer

Field oriented control technique applied to the PMSM without mechanical sensor, based on the cubature KALMAN filter observer

Tensor Product Alternatives for Nonlinear Field-Oriented Control of Induction Machines

The paper presents a nonlinear field-oriented control technique based on the tensor product representation of the nonlinear induction machine model and the solvability of linear matrix inequalities. The nonlinear model has 32 quasi linear parameter-varying equivalent variants, and it is shown that only half of the models result in feasible controller. Two control goals are realized: torque control and speed control. The controller is a nonlinear state feedback controller completed by integral action. A new block diagram is investigated for speed control. The controller gains are designed by the solution of linear matrix inequalities to solve the Lyapunov inequality to obtain a stable and fast response and constraints on the control signal. The presented methods are verified and compared by simulations.

Optimization of Field-Oriented Control for PMSM Motor

This research focuses on designing and simulating a sensorless control technique for optimising field-oriented control to achieve an optimization control applicable to water pressure regulation management. In the irrigation system, water pressure changes are determined by the number of activated emitters operating at different times. Unstable water pressure may reduce irrigation efficiency, leaving brown areas of the landscape not receiving adequate watering. Thus, the Field-oriented control technique is introduced in the paper to regulate the water pressure in the water pump controller using a permanent magnet synchronous motor (PMSM). The PSO-SFC field-oriented control technique for the PMSM was studied to improve motor efficiency and precision motor control over the torque and speed. The cascade-free state feedback controller (SFC) can achieve better dynamics and disturbance compensation in the controller. The SFC's tuning process has been achieved by using a linear-quadratic optimization method and PSO (particle swarm optimization) in the cascaded process. The process improves the coefficient of gain K produced by linear-quadratic optimization and PSO to obtain promising Q and R matrices in the adaptive system with improved output response in the simulation.

Laboratory-Scale Airborne Wind Energy Conversion Emulator Using OPAL-RT Real-Time Simulator

Airborne wind energy systems (AWES) are more efficient than traditional wind turbines because they can capture higher wind speeds at higher altitudes using connected kite generators. Securing a real wind turbine or a site with favorable wind conditions is not always an assured opportunity for conducting research. Hence, the Research and Development of the Laboratory Scale Airborne Wind Energy Conversion System (LAWECS) require a better understanding of airborne wind turbine dynamics and emulation. Therefore, an airborne wind turbine emulation system was designed, implemented, simulated, and experimentally tested with ground data for the real time simulation. The speed and torque of a permanent magnet synchronous motor (PMSM) connected to a kite are regulated to maximize wind energy harvesting. A field-oriented control technique is then used to control the PMSM’s torque, while a three-phase power inverter is utilized to drive the PMSM with PI controllers in a closed loop. The proposed framework was tested, and the emulated airborne wind energy conversion system results were proven experimentally for different wind speeds and generator loads. Further, the LAWECS emulator simulated a 2 kW, 20 kW, and 60 kW designed with a projected kite area of 5, 25, and 70 square meters, respectively. This system was simulated using the Matlab/Simulink software and tested with the experimental data. Furthermore, the evaluation of the proposed framework is validated using a real-time hardware-in-the-loop environment, which uses the FPGA-based OPAL-RT Simulator.

Synergetic-PI controller based on genetic algorithm for DPC-PWM strategy of a multi-rotor wind power system

This work designs a powerful new nonlinear control technique using synergetic control (SC), proportional-integral (PI) controller, and genetic algorithm (GA) for multi-rotor wind energy (MRWE) conversion systems, whereby an asynchronous generator (AG) is used to achieve optimal energy extraction. The direct power control (DPC) technique is used based on the proposed SC-PI-GA (SPI-GA) technique to control the AG-based MRWE system, where this new nonlinear control technique is used to achieve stable control characteristics under random changes in wind speed and to provide great robustness against modeling uncertainties. Moreover, the pulse width modulation (PWM) technique is used to control the AG inverter due to its simplicity and ease of implementation. In this proposed DPC-SPI-GA technique, we need to measure current and voltage to estimate the active power and the reactive power. Also, inner loops are not used in this proposed DPC-SPI-GA technique as is the case in the field-oriented control (FOC) technique, where the proposed system in this work is characterized by an integrated structure. Three different tests are proposed to study and verify the behavior of the designed DPC-SPI-GA strategy compared to the traditional DPC technique.

Robust sensor-less sliding mode of second-order control of doubly fed induction generators in variable speed wind turbine systems based on a novel MRAS-ANFIS observer

The current study proposed a robust sensor-less sliding mode second-order based on a super twisting algorithm (STA-SMSO) approach using a new observer Model Reference Adaptive System-Adaptative Neuro-Fuzzy Inference System (MRAS-ANFIS). This model was applied to a doubly fed induction generator (DFIG) wind turbine running under variable wind speed and DFIG fed with a power voltage source without a speed sensor, while the control objective was used to regulate independently, the active and reactive power DFIG stator were decoupled by using the field-oriented control technique. Additionally, this process reduced the cost of the control scheme and the size of DFIG by eliminating the speed sensor (encoder). In order to improve the traditional MRAS, the MRAS-ANFIS observer was proposed to replace the usual PI controller in the adaptation mechanism of MRAS with an Adaptative Neuro-Fuzzy Inference System (ANFIS) controller. The estimation of rotor position was tested and discussed under varying load conditions in low, zero, and high-speed region. The results mentioned that the proposed observer (MRAS-ANFIS) presented an attractive feature, such as guarantees finite time convergence, good response on speed wind variations, high robustness against machine parameter variations, and load variations compared to the conventional MRAS observer and MRAS-Fuzzy. Hence, the estimated rotor speed converged to their actual value has the capacity for estimating position in deferent region (low/zero/high) of speed.

Backstepping Control Based on a Third-order Sliding Mode Controller to Regulate the Torque and Flux of Asynchronous Motor Drive

This work represents a new nonlinear control for the asynchronous motor (AM) drive. The designed nonlinear control is based on the combination between the backstepping control (BC) scheme and third-order sliding mod control (TOSMC). In this proposed nonlinear control, the torque and flux are controlled. Also, the torque, current, and flux ripples are minimized by a proposed BC-TOSMC strategy. The proposed BC-TOSMC strategy is more robust compared to the field-oriented control (FOC). The proposed BC-TOSMC strategy of AM drive has been simulated in MATLAB/Simulink software. The comparisons were made between the proposed BC-TOSMC strategy and the FOC strategy under different operating conditions. The results show that the proposed BC-TOSMC strategy minimized the flux, current, and torque ripples of the AM drive compared to the FOC strategy, with a reduction torque ripples ratio of about 57.14%. Also, the total harmonic distortion (THD) values of stator current using the proposed BC-TOSMC strategy and FOC technique are respectively 1.09% and 3.42%. In this case, utilizing the proposed BC-TOSMC strategy, the performance of the AM has improved from the FOC strategy.

A New Speed Control Approach of Linear Induction Motor Based on Robust RST Controller and Model Reference Adaptive System Estimator

In this paper, a new model of linear induction motor including the impact of the end-effect on the motor performances is proposed. Moreover, a new strategy of control approach based on the Field-Oriented Control (FOC) technique is suggested and investigated. The proposed approach can provide a robust control strategy and overcome the limitations imposed by FOC technique, which suffers with some drawbacks in linear induction motor (LIM) such as sensitivity to parameter variations and imperfect dynamic tracking performance. In this context, the developed technique combines the benefits provided by the both approaches polynomial (RST) regulator and Model Reference Adaptive System (MRAS) observer, in order to achieve a robust controller by minimizing the external disturbances effects and reducing the influence of parameter variations. Moreover, it is revealed that the proposed conrol approach enables an improved rotor speed response with a reduced number of overshoot values as function of mass variations, where the reccorded maximum overshoot value is 8%. Besides, the devopped controller demonstrates a reducded rise and settling time values under wide applied external force conditions. This confirms that the proposed MRAS-RST technique offers a good dynamic response against the parameter variations. The accuracy and control performance of the proposed technique is checked and validated using Matlab/Simulink environment software tool. Simulation results show the effectiveness of the proposed estimator with improved better robustness for RST controller for different reference tracking and disturbance rejection parameters. These significant results make the proposed approach a promising technique dedicated to the design of high-performance controller, which is highly suitable for industrial and electrical applications.

Sensor Fault Diagnosis Method Based on Rotor Slip Applied to Induction Motor Drive.

A novel diagnosis method based on the rotor slip is proposed in the paper to correctly detect current and speed sensor failures during the induction motor drive (IMD) operation. In order to enhance reliability and avoid confusion in the diagnosis algorithm due to the influence of measured signal quality, each fault type is determined in a priority order defined by the diagnosis method. Based on the features of the IMD applying the field-oriented control (FOC) technique, an innovative model uses the measured currents and reference speed as the input signals to estimate the rotor slip for the current sensor fault detection. After verifying the quality of the feedback of the current signals, a speed sensor fault function is continued, and performs according to relations among the reference speed, estimated speed based on the sliding mode method, and measured rotor speeds. Finally, the estimated quantities are selected to replace the wrong measured current or speed signals. The feasibility of the proposed approach is verified by simulations using Matlab-Simulink software as well as by practical experiments using an IMD prototype with a rated power of 2.2 kW and a DSC-TMS320F28335-based control system. The obtained simulation and experimental results demonstrated the feasibility, effectiveness, and reliability of the proposed diagnosis technique in detecting sensor failures and maintaining the stable operation of the IMD.

Sensorless passivity based control of doubly-fed induction generators in variable-speed wind turbine systems based on high gain observer

The current study presents a robust sensorless control using passivity based control (PBC) combined with high gain observer (HGO). The proposed controller is applied to control the generated doubly-fed induction generator (DFIG) active and reactive power installed on a variable speed wind energy conversion system. The control objective is used to regulate independently the DFIG stator active and reactive power, which are decoupled by using the field oriented control technique. Additionally, this process leads to reduce the cost of control scheme by eliminating the speed sensor. Firstly, the DFIG is modeled under the port controlled Hamiltonian (PCH) model, as well as the method of simultaneous injection damping. Then, the DFIG is further modeled by assignment passivity based on the simultaneous injection damping and assignment (SIDA-PBC) control of the obtained model under such conditions and a comparison with the fuzzy sliding mode controller is carried out. Furthermore, the HGO is selected in order to estimate the rotor position and the speed from the measurement of the DFIG currents and voltages, and compared with fuzzy sliding mode observer. For testing the proposed control scheme performance, a 1.5 MW DFIG system is developed and simulated using MATLAB/Simulink. The obtained results demonstrate the effectiveness of the proposed control scheme in the presence of various DFIG parameters variation. Additionally, the control objective is achieved without speed sensor.

Investigations of hysteresis based direct torque controlled and field oriented controlled IPM drives for electric vehicle applications

Direct Torque Control (DTC) techniques are widely used in the control of AC machines as an opponent of space vector pulse width modulation (SVPWM) based field-oriented control (FOC). In the literature, hysteresis-based DTC (HB-DTC) is a vast majority of DTC techniques as the technique do not require a position resolver or an encoder. In this study, HB-DTC and FOC techniques are compared in detail by paying particular attention to current distortions, torque ripple and computational burden. In both techniques, the results have been obtained by simulating a 4.1 kW interior mounted permanent magnet synchronous (IPM) motor which has been designed and manufactured for research and development for electric vehicle traction applications. The results validate that although the HBDTC drives, have pros such as having less computational burden on the processor and eliminating the need for a position sensor, they have relatively much current distortions and torque ripple and hence the results are much deteriorated. Since the modern processors can easily deal with higher computational burden and field-oriented control is feasible in real time, it has been validated by extensive simulations that FOC based IPM drives are superior to their HB-DTC counterparts.

Intelligent Speed Control and Performance Investigation of a Vector Controlled Electric Vehicle Considering Driving Cycles

In this paper, battery electric vehicle (BEV) controllers are smartly tuned with particle swarm optimization (PSO) and genetic algorithm (GA) to ensure good speed regulation. Intelligent tuning is ensured with a proposed and well-defined cost function that aims to satisfy the design requirements in terms of minimum overshoot, fast response, and tolerable steady state input. Two proposed cost functions are formulated for both simple speed input and for driving cycles. The BEV is controlled with the field oriented control technique (FOC), and it is driven by a permanent magnet synchronous motor (PMSM). An efficient control scheme based on FOC is built using a simplified closed loop control system including BEV components such as regulators, inverter, traction machine, and sensors. Simulation results show that the optimum controller gains obtained by intelligent tuning have resulted in satisfactory BEV performance that sustains the harsh environmental conditions. Robustness tests against BEV parameter changes and environmental parameter variations confirmed the effectiveness of intelligent tuning methods.

Post‐fault operation strategy for single open‐phase fault in three‐phase induction motor drives

Single open-phase fault (SOPF) in three-phase induction motor (TPIM) drives leads to undesired performances and in some cases shutdown of the drive system. This research proposes a post-fault operation strategy based on direct rotor field-oriented control (RFOC) technique for wye-connected TPIM drives during SOPF. In the proposed control system, symmetrical and asymmetrical transformation matrices are utilized for stator voltage and current variables, respectively. In addition, an extended Kalman filter (EKF) is used for the rotor flux estimation, filtration of stator currents, and obtaining their time derivatives. The performance of the introduced technique including steady and transient states during different reference speeds is experimentally validated for a wye-connected TPIM drive considering SOPF. Additionally, the performance of the proposed strategy is experimentally compared with conventional RFOC strategies.

Field-Oriented Control of Five-Phase Induction Motor Fed From Space Vector Modulated Matrix Converter

This paper presents the field-oriented control (FOC) of a five-phase induction motor (FPIM) fed from a three-to-five phase direct matrix converter (DMC). The article focuses on the modulation and control of the three-to-five phase DMC, which discusses minimizing the problems associated with switching vector selection, sector identification, switching sequence selection, and dwell-time calculations. The DMC is controlled from the space vector pulse width modulation (SVPWM) technique, eliminating the x-y components of space vectors. Moreover, the matrix converter can perform unity power factor control at the input side. The FPIM is sourced from a DMC, and the FOC technique is applied to control the drive. The dynamic characteristics of the drive are succeeded for different loading conditions. The proposed work is simulated in Simulink/Matlab environment and further verified through practical experimentation. The control signals of the IGBTs are generated through FPGA embedded in dSPACE 1006. The experimental and the simulation results prove the practicability of the FOC to FPIM fed from a DMC.

A field-oriented control (FOC) method using the virtual currents for the induction motor drive

<span lang="EN-US">An improving field-oriented control technique without current sensors is proposed to control rotor speed for an induction motor drive. The estimated stator currents based on the slip frequency are used instead of feedback current signals in the FOC loop. The reference signals and the estimated currents through computation steps are used to generate the control voltage for the switching inverter. Simulations were performed in Matlab/Simulink environment at rated speed and low-speed range to demonstrate the method's feasibility. Through simulation results, the FOC method using virtual sensors has proved its effectiveness in ensuring the stable operation of the IMD over a wide speed range.</span>

Modified PWM Technique for a Multi-Pulse Converter Fed Multilevel Inverter Based IM Drive

This article presents a 36-pulse converter and five-level cascaded H-bridge multilevel inverter (CHB-MLI) fed medium voltage induction motor drive (MVIMD) system. The multiwinding transformer (MWT) for a 36-pulse ac–dc converter is designed in such a way that it requires the least number of windings and enhances power quality at the grid end. This is helpful to reduce the size, weight, and cost of the presented MVIMD. The modified carrier level shifted pulsewidth modulation (MC-LSPWM) is used to control five-level CHB-MLI fed induction motor, which adheres the power quality standard IEEE519 at drive end. The main characteristic of used PWM is that it has inherent rotating switching pattern nature, which is helpful to enhance the power quality performance and to decrease the continuous conduction time of the H-bridge. Whereas, this continuous conduction among H-bridges, is not balanced in the level-shifted pulsewidth modulation (LSPWM). Therefore, conduction losses among the H-bridges of CHB-MLI are balanced and reduced by this MC-LSPWM for continuous operation, which is not possible with the conventional LSPWM. The practicality of this MVIMD with an indirect field-oriented control and MC-LSPWM technique, is substantiated via a comparison with the configuration reported in the literature, simulation, and experimentation, respectively. Performance of the drive system is evaluated during different operating conditions, such as starting, steady-state, speed and load perturbations. Further, a detailed comparative analysis of results is presented, which demonstrates that presented MWT configuration has fewer number of windings (only thirty-three windings), less conductor material and minimum losses. Thus, the presented configuration of MVIMD shows excellent performance characteristics with reduced size and weight such as currents total harmonic distortion is 2.5% (grid end), 3.66% (drive end) and efficiency of the drive is 88.101%, when the drive runs at rated conditions.

Field Oriented Control of AFPMSM for Electrical Vehicle Using Adaptive Neuro-Fuzzy Inference System (ANFIS)

Axial Flux Permanent Magnet Synchronous Motor (AFPMSM) are very attractive candidates for driving applications due to their high efficiency, high torque-to-weight ratio, high power density, small magnetic thickness, and simplicity of construction. On the other hand, AFPMSM produces undesirable torque ripple in the developed electromagnetic torque, affecting their output performance. An intelligent control method is proposed in this paper to reduce torque ripple and improve the dynamic performance of AFPMSM. The vector control, employing the Field Oriented Control (FOC) technique, was used to improve the dynamic performance of the AFPMSM. The speed and torque controllers are achieved using the decoupling method. The intelligent control was designed to improve the performance of AFPMSM obtained from PI-PSO. The Adaptive Neuro-Fuzzy Inference System (ANFIS) was used as an Intelligent controller to integrate both the speed and torque constraints in a single training procedure. Training data for ANFIS was obtained from PI-PSO with a multi-objective cost function that includes the torque ripple and speed response criteria. The approach gave great results in terms of speed performance in different operating conditions and in tracking the required speed in load and no-load. In addition, the torque ripple was reduced by 10.04% and 46.67% compared with PI-PSO and Multi-objective cost function of speed, respectively.