Finite control set and modulated model predictive flux and current control for induction motor drives

The paper presents a new implementation of direct flux and current vector control of an induction motor drive using the techniques of model predictive control. The advantages offered by predictive control are used to enhance the dynamics of direct flux vector control. To minimize the problems of variable switching frequency inherent to finite control set predictive control, an alternative approach using pulse width modulation is studied for command execution as occurs in the so-called modulated model predictive control. A comparison between finite control set and modulated model predictive control is presented and the results are also compared with the control implementation through traditional proportional-integral regulators to highlight the advantages and drawbacks of predictive control based strategies. Apart from a greater harmonic content in stator currents, the predictive control can offers control dynamics comparable with proportional-integral control while maintaining immunity against machine parameter variations and excluding the need for controller tunin

Performance Improved Active Power Filter Using Fuzzy Based Adaptive Controller for Renewable Power Generation Systems

An Active power filter implemented with a four-leg voltage-source inverter utilizing a predictive control scheme is introduced. The utilization of a four-leg voltage-source inverter permits the pay of current consonant parts, and in addition lopsided current created by single-stage nonlinear burdens. A point by point yet straightforward numerical model of the dynamic power channel, including the impact of the identical power framework impedance, is determined and used to plan the prescient control calculation. The pay execution of the proposed dynamic power channel and the related control plan under enduring state and transient working conditions is shown through reproductions results. As of late, fuzzy logic controller was connected for active power filter (APF) control application, as the APF is only a current controlled VSI. In this paper, a fuzzy logic based shunt APF is displayed in light of the compelling time idea. The viable time idea disposes of the trigonometric counts and part ID, along these lines it lessens the computational exertion. Reenactment results show the viability of the APF with the fuzzy logic based control procedure. Reproduction results are acquired for both PI controller and fuzzy logic controller and the outcomes are thought about. In the fuzzy controlled four leg inverter APF is utilized for power quality change

Analysis of ANN Based Active Power Filter Performance For Renewable Power Generation System

In this paper analysis of ANN based active power filter performance for renewable power generation system has been proposed. A four leg VSC is used in this system, and this allows the reparation of current harmonic components, as well as unbalanced current generated by single-phase nonlinear loads. A new ANN controller has been proposed to improve the %THD in the non linear current. Generally the PI controller has more %THD; the ANN controller has more effect and will reduce the %THD. %THD table shows the differences between conventional controller and ANN controller. The simple numerical model of the active power filter, together with the effect of the equivalent power system impedance, is derived and used to design the analytical control algorithm. The simulation result shows the efficiency of the system using MATLAB/SIMULATION software. The reimbursement performance of the proposed active power filter and the associated control scheme with ANN controller have been tested under stable status and transitory operating environment through the simulation results

An Improved Performance Of Pid And Fuzzy Controller Based Sapf For Wind And Solar Power Generation

Amid the previous existences a while, fuzzy controller depends on fuzzy logic included manages in a sure level of ideas can't be communicated as the " genuine" or "false" however a bit "in part genuine" are most dynamic and productive ranges for examination arranged applications particularly in the domain of mechanical procedure of data yield relations. The compensator is proposed for use with every individual distributed span (DS) framework in the smaller scale matrix, and comprises of two four - leg inverters (an arrangement and a shunt), ideally controlled to accomplish an improvement of both the nature of force inside of the miniaturized scale network and the nature of streams existing between the small scale lattice and usage framework. The reason for a four-leg voltage-source inverter (4LVSI) allow the pay of current consonant fixings, incorporating unequal current created in single-stage nonlinear burdens. An exact straightforward numerical model of shunt dynamic channel, including the impact of force framework impedance, is give and used to outline the prescient control calculation. The essential pay of the proposed shunt dynamic force channel and took after control plan for relentless state and transient occurrence conditions is displays for the nature of force through test results by MATLAB/SIMULINK

Model predictive control of a dual induction motor drive fed by a single voltage source inverter

In dual induction motor control applications, averaging of controlled variables, mean circuit models, or master/slave strategies are used, which lead to unbalanced and unstable operation of the overall drive system. An improved finite control set predictive torque control (FCS-PTC) method is proposed for the parallel operation of two induction motors. The optimization cost function of the controller is shown to meet multiple objectives simultaneously, eliminating the use of averaging techniques and without leading to unbalanced conditions. The simulation results are compared with direct torque control (DTC) for dual induction motors. As compared to DTC, model predictive control shows low torque and flux ripple, 5% lower current THD, improved current balancing between the motors, and negligible effect of parameter mismatch

Anti-disturbance sliding mode based deadbeat direct torque control for PMSM speed regulation system

Deadbeat direct torque control (DBDTC) calculates the voltage vector based on the motor mathematical model and tracks the torque and flux reference within only one sampling cycle. However, in the traditional DBDTC, the reference torque is generated by a speed PI controller, which presents a low dynamic and poor precision, particularly under external disturbances. To sort out this issue, this paper proposes an improved DBDTC control method basing on the sliding mode strategy. First, an anti-disturbance sliding mode controller (ASMC) is presented which is superior in offering a fast and accurate reference torque for DBDTC. Along the way, an extended sliding mode disturbance observer is introduced which estimates total disturbances and compensates the sliding mode controller. To reduce the chattering of sliding mode control, a novel reaching law is proposed. This novel reaching law introduces system state variable in the exponential terms of power reaching law, and meanwhile including an adaptive exponential reaching action. By this means, it increases system convergence rate to the sliding mode surface while suppressing sliding mode chattering. Finally, both simulation and experimental results show that the proposed control method has better performance in terms of torque ripple reduction, speed dynamic response

Modified Direct Torque Control of Induction Motor Drives

Over past years, direct torque control (DTC) has proven to be a powerful technique for controlling induction motors since, its simple structure, fast performance, and robustness. However, conventional DTC has a major problem in selecting the optimum voltage vector in order to provide fast torque response, due to the nature of the hysteresis controller. This thesis presents a new control topology for DTC, which enables fast torque response and reduced steady state ripple. The proposed scheme utilizes an optimized inverter voltage vector selection process ensuring a higher rate of torque increment during transient periods. Further, two nonlinear adaptation mechanisms are used to replace the hysteresis controllers thus obtain enhanced torque and stator flux regulation. One scheme is based on sliding mode theory and the other method is based on fuzzy logic strategy. A comprehensive simulation study has been performed to evaluate the performances of the proposed sector-advancing algorithm under the two nonlinear control methodologies. The corresponding simulation results and discussion are presented for each section. It is concluded that the proposed DTC algorithms with sliding mode and fuzzy logic strategies demonstrate better characteristics in both transient and steady state operation with regards to the conventional DTC.Electrical Engineerin

Control predictivo del convertidor multinivel con enclavamiento por diodos y sus aplicaciones en media tensión

En esta tesis se realiza el estudio del convertidor multinivel con enclavamiento por diodos. Se presenta un algoritmo generalizado para el control del balance de las tensiones del bus de continua del convertidor que no requiere de circuitos adicionales de balance. También se realiza un análisis de las características de conmutación de la topología y se elaboran reglas que aseguren el funcionamiento seguro de las llaves de potencia. Se desarrolla un algoritmo de control predictivo de estados finitos en el cual se unifica el control de las variables externas del convertidor (corrientes, potencias o variables internas de la carga) con el algoritmo de control de balance. Se consideran las restricciones de conmutación propias de la topología con el propósito de asegurar la operación correcta del convertidor y el sistema que lo circunda. Se analiza el desempeño del convertidor y la técnica desarrollada en aplicaciones de acondicionamiento de potencia, accionamientos eléctricos y generación eólica. Los algoritmos se ensayan mediante simulación en las aplicaciones mencionadas.An in depth study of the Diode Clamped Multilevel Converter is performed in this Thesis. The DC bus voltage unbalance problem of the topology is presented and the development of a generalized algorithm for voltage balance control of the DC bus capacitors is addressed which does not need any additional balancing circuits. An analysis is presented concerning the switching constraints of the converter and the synthesis of a switching rule that ensures correct voltage clamping of the power devices. Also, a Finite Control Set Model Predictive Control strategy is developed to merge the voltage balancing algorithm with the control of external variables (currents, power or intrinsic load variables). This algorithm incorporates the switching restrictions of the topology in order to ensure the proper operation of the converter and the control of the external system. The performance of the control algorithm is evaluated by means of computer simulations in applications such as power conditioning, motor drives and wind power conversion.Facultad de Ingenierí

Control strategy for a mono-inverter multi-PMSM system - Stability and efficiency

During these decades, Permanent Magnet Synchronous Motor (PMSM) has become a vital part of military, industry and civil applications due to the advantages of high power density, high efficiency, high reliability and simple structure, small volume and light weight. Sometimes, multiple PMSMs are used to carry out cooperative functions. For example, the bogie of a locomotive, the flight control surface of an airplane. These PMSMs usually operates at the same speed. To reduce the volume and weight, an idea of sharing the static power conversion devices, which is called Mono-Inverter Multi-PMSM system (MIMPMSM), is raised. Although many researchers have given different controller solutions for the MIMPMSM system, most of them are not clear in the aspects of system stability and efficiency issues. This has become the biggest obstacle to the practical use of MIMPMSM. Oriented with these problems, starting with a MIMPMSM system with 2 motors, in the first step, we have tested some control strategies by an experiment to verify the feasibility and performance of them. In final, based on the experiment data, we have figured that the overconstraint problem exists in some control strategies. Then, an analysis and controller design based on steady-state model of a Mono-Inverter Dual-PMSM (MIDPMSM) system is carried out.By studying the solution existence problem of the steady-state model, we give out the design guideline to the controller structure. Combining the open-loop stability and steady-state solution, the region of controllability and stability is obtained. Lagrange Multiplier is used develop theexpression of efficiency-optimal steady-staterelated to torque and speed. The experiment has shown that the efficiency of the new controller has improved significantly. Meanwhile, we have explored the influence of parameter variation in system stability and efficiency-optimization. The variation will influence the stability region. But its influence can be eliminated by using Master- Slave strategy. On the other hand, in the aspect of efficiency optimization, the simulation results have shown that parameter mismatch, especially the permeant flux, can cause high efficiency loss. In the last step, this controller is also adapted to a MIMPMSM system with more than two motors. The simulation results demonstrate the effectiveness