A short predictive Model Predictive Control (MPC) approach for hybrid characteristics analysis in DC-DC converter

Historically, the MPC has been successfully applied in drives system for over a decade. Furthermore, the DC-DC converter naturally deals with high switching phenomenon that contributes to the challenging in control approach. Its operation conventionally associated with PI/PID controller in order to meet the desired output. However, the PI/PID controller lacking in getting a good transient response since this controller highly depends on the controller gains. Recently, an advanced controller has been proposed in the literature for the purpose to enhance the DC-DC converter performance. Hence, in this thesis, the short prediction horizon of MPC using search tree optimization that generates low switching states phenomenon is proposed. The MPC algorithm is developed based on the hybrid characteristic signals from the DC-DC converter. The load changes due to the increasing or decreasing the loads (could be happened of heating effect) will affect the tracking of the output voltage. The Kalman Filter (KF) is used for load estimation for smoothing and tracking the output voltage. The performance of short prediction horizons is being compared to PI controller in terms of transient response during the start-up scenario. The results show that the proposed controller has a better response than PI controller, which is the overshoot has been reduced to more than 50% and the settling time more faster about 25% than PI controller during start-up scenario. Therefore, this control approach for DC-DC buck converter has produced the promising output transient performance when compared with the conventional PI controller while also minimizing the switching sequence phenomenon

MODELLING A THREE-PHASE CURRENT SOURCE INVERTER

A current source inverter model has been developed in the given paper that is constructed from six LTI models for the different switching modes. The overall model is in a piecewise affine form that supports the use of model predictive control. The model has been verified against engineering expectations and its open-loop performance shows that it is a promising basis of model predictive control structures

A novel sliding mode controller for DC-DC boost converters under input/load variations

© 2015 IEEE. In this paper a simple sliding mode controller based on the averaging state space model is proposed for a DC-DC boost converter. It is demonstrated to be easily implemented and has time-variant sliding coefficients. The proposed controller can effectively regulate the output voltage by controlling the switch states (through the dynamic duty cycles) even when the input voltage, load or output command varies. Furthermore the controller is independent of the inductor current and the load, although the load value is needed when designing the sliding coefficients. The constant switching frequency is maintained thus simplifying the design procedure, enhancing the regulation properties and benefiting the filter design. The controller has good dynamic response, overshoot damping and robustness. Comparative simulations are carried in MATLAB/Simulink between the proposed approach and a widely used PID controller to verify the effectiveness and feasibility of the proposed method

Sintonización geométrica de controladores desde un enfoque basado en datos

PRELIMINARIES: Fine tuning of PI controllers implies the explicit knowledge of a mathematical model for the system as well as trial and error calculations. GOAL: To perform calculation of parameters of PI controllers by means of a data-driven approach based on frequency response data. METHODOLOGY: The basis of the proposed approach is the geometrical interpretation for stability margins and their relationship to the stabilizing set of controllers achieving performance specifications. Application on electrical systems involving boost power converters is employed as illustrative example of the proposed technique. RESULT: An experimental Bode diagram allowed the calculation of control parameters without an explicit knowledge of system analytical models. CONCLUSION: Regulation of electrical variables of the power converter was successfully verified by numerical simulations and experimental tests, satisfying limit constraints on saturation levels for practical stabilizing sets.ANTECEDENTES: Sintonizar controladores PI por métodos convencionales implica conocer el modelo de la planta y aplicar técnicas de ensayo y error. OBJETIVO: Ajustar los parámetros de un compensador PI a partir de una metodología de control basado en datos de respuesta frecuencial. MÉTODO: La base del cálculo presentado es la interpretación geométrica para los márgenes de estabilidad del sistema, constituyendo un espacio de especificaciones dinámicas viables. Se presenta el análisis por simulación y la validación experimental en laboratorio para sistemas eléctricos involucrando convertidores electrónicos de potencia CC-CC del tipo elevador. RESULTADO: La construcción de un diagrama de Bode experimental permitió eliminar la dependencia en el cálculo de parámetros del controlador respecto al conocimiento explícito de un modelo analítico del sistema. CONCLUSIÓN: A través de simulaciones numéricas y mediciones en laboratorio fue posible verificar la regulación dinámica del convertidor de potencia, incluyendo restricciones de saturación para establecimiento de conjuntos estabilizantes

Hybrid System Identification of Manual Tracking Submovements in Parkinson\u27s Disease

Seemingly smooth motions in manual tracking, (e.g., following a moving target with a joystick input) are actually sequences of submovements: short, open-loop motions that have been previously learned. In Parkinson\u27s disease, a neurodegenerative movement disorder, characterizations of motor performance can yield insight into underlying neurological mechanisms and therefore into potential treatment strategies. We focus on characterizing submovements through Hybrid System Identification, in which the dynamics of each submovement, the mode sequence and timing, and switching mechanisms are all unknown. We describe an initialization that provides a mode sequence and estimate of the dynamics of submovements, then apply hybrid optimization techniques based on embedding to solve a constrained nonlinear program. We also use the existing geometric approach for hybrid system identification to analyze our model and explain the deficits and advantages of each. These methods are applied to data gathered from subjects with Parkinson\u27s disease (on and off L-dopa medication) and from age-matched control subjects, and the results compared across groups demonstrating robust differences. Lastly, we develop a scheme to estimate the switching mechanism of the modeled hybrid system by using the principle of maximum margin separating hyperplane, which is a convex optimization problem, over the affine parameters describing the switching surface and provide a means o characterizing when too many or too few parameters are hypothesized to lie in the switching surface

Control ponderado por replicator dynamics para un convertidor de potencia dc-dc tipo boost

Un problema en el marco de referencia de la electrónica de potencia que involucra varios escenarios prácticos para un convertidor de potencia DC-DC clásico de frecuencia fija sincrónica, se investiga. Una nueva técnica de control ponderado que utiliza los conceptos de replicator dynamics para ponderar la operación de diferentes controladores sintonizados para operar en diferentes modos y con diferentes objetivos de control, es aplicada al convertidor Boost. Estos cálculos son validados con simulaciones y resultados experimentales para tres condiciones críticas tales como nominal, variaciones de tensión de entrada, y perturbaciones de carga. Por último, el comportamiento de un caso de estudio es comparado a través de pruebas experimentales. Los resultados demuestran un mejor desempeño para la nueva técnica de control presentada en comparación con las técnicas clásicas en modelo promedio tales como el control PID.A power electronics benchmark problem involving several practical scenarios for a fixed-frequency synchronous classical DC-DC power converter is investigated. A new weighted control technique that uses the replicator dynamics concepts to weight the operation of different controllers tuned to operate in different modes, and with different control objectives is applied to the Boost converter. These calculations are validated with simulations and experimental results for three critical conditions such as nominal, input voltage variations, and load perturbations. Finally, the behavior of one case of study is compared through experimental tests. The results have shown better performance for the presented novel control technique compared to the classical techniques in average model such as PID control.Ingeniero (a) ElectrónicoPregrad

Comparison of hybrid control techniques for buck and boost DC-DC converters

WOSInternational audienceFive recent techniques from hybrid and optimal control are evaluated on two power electronics benchmark problems. The benchmarks involve a number of practically interesting operating scenarios for fixed-frequency synchronous dc-dc converters. The specifications are defined such that good performance can only be obtained if the switched and nonlinear nature of the problem is accounted for during the design phase. A nonlinear action is featured in all methods either intrinsically or as external logic. The designs are evaluated and compared on the same experimental platform. Experiments show that the proposed methods display high performances, while respecting circuit constraints, thus protecting the semiconductor devices. Moreover, the complexity of the controllers is compatible with the high-frequency requirements of the considered application