Showing papers by "Juan I. Yuz published in 2009"
TL;DR: A new and simple control scheme using predictive control for a two-level converter using a model of the system to predict the behavior of the output voltage for each possible switching state is presented.
Abstract: The use of an inverter with an output LC filter allows for generation of output sinusoidal voltages with low harmonic distortion, suitable for uninterruptible power supply systems. However, the controller design becomes more difficult. This paper presents a new and simple control scheme using predictive control for a two-level converter. The controller uses the model of the system to predict, on each sampling interval, the behavior of the output voltage for each possible switching state. Then, a cost function is used as a criterion for selecting the switching state that will be applied during the next sampling interval. In addition, an observer is used for load-current estimation, enhancing the behavior of the proposed controller without increasing the number of current sensors. Experimental results under linear and nonlinear load conditions, with a 5.5-kW prototype, are presented, verifying the feasibility and good performance of the proposed control scheme.
578 citations
TL;DR: A predictive control algorithm that uses a state-space model of an induction machine with time-varying components improving the accuracy of state prediction and a high degree of flexibility is obtained with the proposed control technique due to the online optimization algorithm.
Abstract: In this paper, we present a predictive control algorithm that uses a state-space model. Based on classical control theory, an exact discrete-time model of an induction machine with time-varying components is developed improving the accuracy of state prediction. A torque and stator flux magnitude control algorithm evaluates a cost function for each switching state available in a two-level inverter. The voltage vector with the lowest torque and stator flux magnitude errors is selected to be applied in the next sampling interval. A high degree of flexibility is obtained with the proposed control technique due to the online optimization algorithm, where system nonlinearities and restrictions can be included. Experimental results for a 4-kW induction machine are presented to validate the proposed state-space model and control algorithm.
432 citations
TL;DR: Some approximations of a two dimensional continuous-time signal spectrum developed from the sampled-data spectrum are studied, exploring the possibility of retrieving the underlying continuous- time system from samples of the input and output signals.
6 citations
TL;DR: This paper considers the analysis of multiple-input multiple-output systems using the Participation Matrix, which provides a tool both for interaction measure and controller structure selection and presents novel interpretations in the time and in the frequency domain based on definition of Hilbert-Schmidt-Hankel norm.
Abstract: In this paper we consider the analysis of multiple-input multiple-output systems using the Participation Matrix, which provides a tool both for interaction measure and controller structure selection. For this matrix we present novel interpretations in the time and in the frequency domain, based on definition of Hilbert-Schmidt-Hankel norm. Moreover, the time domain interpretation is exploited to obtain an empirical estimate of the participation matrix directly from input-output data of the multivariable system.
5 citations
TL;DR: Different maximum likelihood formulations have been proposed in the literature for dynamic system identification in the time and frequency domains as discussed by the authors, and numerical examples to study and compare these approaches for short and long data sets.