This paper discusses a simple approach to the sensor less speed control of a PMSM drive, targeted to sailboat propulsion systems. The rotor position estimate, required for field orientation, is usually obtained directly from the estimated back-emf, whenever the speed surpasses a minimum value. During startup, an open-loop observer, based on the mechanical model of the drive, is employed to yield the rotor position estimate. Theoretical discussions are presented, followed by experimental results that demonstrate the viability of the proposed technique.

This paper presents a PWM family of ZVT self-resonant converters that use a magnetic coupling to accomplish the minimum total losses point of the auxiliary switch. Their great advantage is the overall size reduction, because allows to reduce the auxiliary switch heatsink as well as the number of magnetic components of the circuit, once the auxiliary inductor is incorporated into the main one. This fact also reduces the number of radiated EMI sources. A design procedure and a design example are presented, as well as experimental results obtained from a 500 W, 120/300 VDC, 100 kHz prototype of the boost converter, confirming the operation of the proposal and the benefits obtained by its use

This paper discusses an induction generator (IG) system that provides regulated voltage at any load condition. It utilizes the classical self-excitation principle but, in addition to that, it makes use of a current regulated PWM inverter to control the output voltage magnitude. It is primarily intended for micro hydro plants to be used in rural areas, where the cost of conventional distribution system is high, and the water resources are available to drive an unregulated low head turbine. The proposed topology is presented, followed by an analysis of the control structure. The methodology is validated via simulation studies.

This paper presents the use of a magnetically-coupled regenerative snubber applied to PWM power converters operating in the continuous conduction mode (CCM). The operation analysis and design is carried out on a buck converter, but is easily extensible to the others. The proposed snubber use the main core of the DC-DC converter to build the resonant inductor, reducing component count. This is a useful new solution to reduce switching losses through passive snubbers. Experimental results are presented to validate the study.

Low switching-frequency converters are a good alternative if weight and size are not a restriction. Their main features are reduced EMI emission and low switching losses. This paper performs a comparison among three low-switching frequency three-phase rectifiers. Some new important information are introduced in the paper, such as a dynamical model to design the control loop and components rating. Experimental results complete the exposition.

Duty-cycle modulation of single-switch three-phase boost rectifiers has been demonstrated to be an effective way of reducing their input current harmonics. But a converter design methodology for such control approach is not available yet. This paper intends to fulfill this lack, presenting a design approach for this operation mode. Design equations are provided for some operation conditions, and experimental results validate the approach.

Classical control methods are still employed in industry. Proper design and tuning of the controllers are essential for the acceptable performance of the controlled system. In the past, a considerable number of methods have been developed for this purpose. This paper presents a novel, alternative technique of controller design based on genetic algorithms and a laboratory-scale direct current drive as application example. Experimental results show the potential of the method.

Interval based control is a non conventional control technique recently introduced. The objective is the automatic control of physical systems represented by imprecise mathematical models. In this paper, the interval based control technique is applied to a mechanical arm with one degree of freedom

In general, the input current of an AC/DC electronic converter contains a considerable number of harmonics. To reduce the harmonic effects within levels allowed by a future norm, the IEC555-2, a preconditioner based on a switched mode power supply can be used. But the employment of a preconditioner or power factor corrector may cause undesirable HF-distortion and dissipation. This paper describes two preconditioners and in addition, presents measurements for the purposes of comparison of electromagnetic compatibility (EMC)

Nonconventional control techniques (fuzzy logic control, neural control, numerical based fuzzy control etc.) have been fully used to implement automatic control of physical systems. In this paper, a novel nonconventional control technique, namely “interval based control”, is presented. The objective is the automatic control of physical systems represented by imprecise mathematical models. For the purpose of investigating the basic performance of the newly developed technique, one laboratory-scale plant was used, viz. a crane with two degrees of freedom. Experimental results, including a comparison with the conventional state variable feedback control technique, are also presented

In this work, the authors propose a new control technique, namely, "interval based control". The objective is the automatic control of physical systems, represented by imprecise mathematical models. A new physical systems representation form has been introduced and a general procedure to perform automatic control has been fully described. To illustrate the method, a successful application (crane motion control), using the interval based control technique has been presented, and the experimental results shown.

In this work we propose a new control technique, namely, Based Control. The objective is the automatic control of physical systems, represented by imprecise mathematical models. A new physical systems representation form has been introduced and a general procedure to perform automatic control has been fully described. To illustrate the new method, a successful application (crane motion control), using the Interval Based Control Technique has been presented, and the experimental results shown,

The employment of PID controllers for automated processes has been widely accepted in industry. The main problems associated with classical PID controllers are tuning and robustness in case of changes in system conditions. In this paper, a novel and more robust controller is proposed, viz a numerical-based fuzzy PID controller or extremities PID controller, which combines classical PID concepts with fuzzy arithmetics. For the purpose of investigating the basic performance of the newly developed controller, two laboratory-scale plants are used, viz a simple series RLC network and a microcomputer-based dual-converter DC drive. Experimental results, including comparisons with a classical PID controller, are also presented

Classical PID controllers have been widely accepted in the industry. Problems associated with this type of controller are tuning and robustness for various system conditions. This paper presents a novel and robust controller, i.e. the Extremities PID controller based on methods of fuzzy arithmetics and conventional PID concepts. The controller has been applied to a simple RLC network and experimental results, including comparison with the classical PID, show very satisfactory performance of the proposed controller.

This paper presents the systematic design of a fuzzy logic controller for a carpendulum mechanical system, well known in the literature as the inverted pendulum problem. The system is non-linear and inherently unstable. The objective of the controller is to maintain the pendulum in its inherently unstable position (vertical and upward oriented) using only fuzzy logic techniques. The proposed method controls the pendulum on the assumption of a track of infinite length. The validity of the approach has experimentally been verified and the results show the viability of the method. This work is part of a study on nonconventional control techniques applied to dynamic systems.

In this paper a design method which determines PI/PID parameters of motion control systems based on genetic algorithms (GAs) is presented. First, a brief review is given of an analytical procedure to obtain optimal PI/PID parameters by minimization of the integral of time multiplied-squared error in the frequency domain. Next, a computationally simple procedure based on real-coded GAs with appropriate operators is described and a synthesis method is proposed. Simulation results are given which show the validation of the design method.