Antonio Valderrabano-Gonzalez

Output feedback control of a mechanical system using magnetic levitation.

This paper presents an application of a nonlinear magnetic levitation system to the problem of efficient active control of mass-spring-damper mechanical systems. An output feedback control scheme is proposed for reference position trajectory tracking tasks on the flexible mechanical system. The electromagnetically actuated system is shown to be a differentially flat nonlinear system. An extended state estimation approach is also proposed to obtain estimates of velocity, acceleration and disturbance signals. The differential flatness structural property of the system is then employed for the synthesis of the controller and the signal estimation approach presented in this work. Some experimental and simulation results are included to show the efficient performance of the control approach and the effective estimation of the unknown signals.

Hybrid Voltage‐Multipliers Based Switching Power Converters

Abstract. This work presents a derivation of PWM DC-DC hybrid converters by combining traditional converters with the Cockcroft–Walton voltage multiplier, the voltage multiplier of each converter is driven with the same transistor of the basic topology; this fact makes the structure of the new converters very simple and provides high-voltage gain. The traditional topologies discussed are the boost, buck-boost, Cuk and SEPIC. They main features of the discussed family are: (i) high-voltage gain without using extreme duty cycles or transformers, which allow high switching frequency and (ii) low voltage stress in switching devices, along with modular structures, and more output levels can be added without modifying the main circuit, which is highly desirable in some applications such as renewable energy generation systems. It is shown how a multiplier converter can become a generalized topology and how some of the traditional converters and several state-of-the-art converters can be derived from the generalized topologies and vice-versa. All the discussed converters were simulated, additionally experimental results are provided with an interleaved multiplier converter.

Adaptive neural network control of chaos in permanent magnet synchronous motor

AbstractPermanent magnet synchronous motors have been used as variable-speed drives, especially for speed control and position, but it exhibits chaotic performance under certain parameter’s changes. This work presents the use of a B-Spline neural network scheme to stabilize chaos and to adjust the rotor speed of synchronous motors. The B-spline neural network is an efficient tool to implement the adaptive speed control, with the possibility of carrying out this task on-line, taking into account the systems non-linearities. One of the main tasks is the adjustment of the proportional-integral parameters for rotor speed controller. In this work, a neural network algorithm is used to solve this problem. A nonlinear observer is designed for estimation of the rotor speed and load torque. The results of numerical simulations demonstrate that the permanent magnet synchronous motors with the B-Spline control scheme has a good dynamic performance and steady state accuracy.

A hybrid interleaved/switched-capacitor boost converter

This paper proposes a boost dc-dc converter topology with the capability of canceling the input current ripple at an arbitrarily preselected duty cycle, high-voltage gain without utilizing extreme values of duty cycle or boosting transformers, it contains a switched-capacitor structure in which the current among capacitors is continuous. The paper provides details on the principle of operation via topological considerations and a mathematical model. The key factor of reactive components sizing is also discussed. The converter was validated in the laboratory through the construction of a hardware prototype.

Quadratic gain converter with output voltage ripple mitigation

This paper introduces a DC-DC converter topology with the following features: (i) quadratic voltage gain, which allows the converter to work with wide voltage line variations in a wide operation voltage range with a minimal variation of duty cycle and without the use of extreme duty cycles; (ii) output voltage ripple mitigation, this feature can be accomplished in a specific duty cycle by proper selection of components and PWM signals. The proposed converter can be designed to have zero output voltage ripple for the nominal gain (duty cycle), this allows the use of small values of capacitance. The operating principles and steady-state equations, for the discussed topology in CCM are presented in detail. Experimental tests are presented to validate the propositions.

Analysis and Implementation of an 84-Pulse STATCOM

This chapter describes the use of STATCOM for the reactive power compensation and the power quality improvement. The assembling of a Voltage Source Converter (VSC) that meets the IEEE Recommended Practices and Requirements for Harmonic Control in Electrical Power Systems (IEEE Std. 519-1992) is emphasized. The low Total Harmonic Distortion (THD) that this VSC generates, qualifies this power conditioner to be considered for its use on stringent applications. The reinjection principle is used, that makes this proposal be considered as an affordable solution to the sinusoidal synthesis due to the reduced number of switches. The reinjection transformer is one of the most important elements in this configuration, and it can have a wide turn ratio variation without leading out the special application standards. Conventional Proportional-Integral (PI) controllers are applied to hold the output voltage of the STATCOM around nominal conditions. The followed strategy employs the error and its variation to break down the control action into smaller sections that can be selected according to simple rules.

Study of STATCOM in abc Framework

In this chapter, the STATCOM characteristics are analyzed when it is utilized for improving the voltage stability. This chapter aims to analyze the STATCOM in the abc coordinates, and its impact over the power system under steady state and transient conditions is studied. Mathematical description of the main components is included to represent the dynamic behavior. These elements are formulated by differential equations in order to demonstrate how the STATCOM influences overall power system performance and voltage stability margins. The proposed methodology is validated on a Synchronous Machine Infinite Bus (SMIB) and on the New England test power system, which comprises 39-buses, 46-transmission lines, and 10-generators.

Signal differentiation in position tracking control of dc motors

An asymptotic differentiation approach with respect to time is used for on-line estimation of velocity and acceleration signals in controlled dc motors. The attractive feature of this differentiator of signals is that it does not require any system mathematical model, which allows its use in engineering systems that require the signal differentiation for its control, identification, fault detection, among other applications. Moreover, it is shown that the differentiation approach can be applied for output signals showing a chaotic behavior. In addition a differential flatness control scheme with additional integral compensation of the output error is proposed for tracking tasks of position reference trajectories for direct current electric motors using angular position measurements only.

Bootstrap Cascaded Multilevel Converter

This paper presents a cascaded-type multilevel inverter whit only one DC voltage source, which uses a floating capacitor to feed the other cascaded H-bridge, the capacitor is charge in a bootstrap technique and then the converter can provide a peak voltage equal to twice the DC-source regard-less on the power factor in the load, the converter is ideal for renewable systems applications as inverter stage in energy generation or grid integration, experimental results with a 5-level prototype verify the converter behavior.