Jose Manuel Aller

• Doctor of Engineering
• Professor (Full) at Universidad Politécnica Salesiana Cuenca Ecuador

This paper presents an equivalent circuit of the singlephase asymmetric induction machine based on the VBR (Voltage Behind Reactance) model, which is a Thèvenin equivalent, valid in transient and steady-state conditions. This model allows the electromechanical converter to be represented in circuit calculation programs such as Simulink, Proteus, PS...

This paper presents an experimental evaluation of the voltage unbalances effects in the efficiency of induction motors. In that sense, two distinct National Electrical Manufacturers Associations (NEMA) design were evaluated to seek the changes on their performance. The voltage unbalance was assessed using the Complex Voltage Unbalance Factor (CVUF)...

A parameter estimation method for deep-bar induction machines is presented. The parameters are estimated using two instantaneous voltage and current waveforms during a direct startup. The instantaneous input impedance is used as a stator indicator to solve a constrained nonlinear optimization problem that outputs the model’s parameters. For such pu...

This paper presents a direct and approximate model of PV cell that considers variations in surrounding temperature and solar irradiation. The method uses the one diode model approximation and PV parameters from the manufacturer's data, together with a selective (first or second order) Taylor series. In this paper, a recursive solution for the PV ce...

Switched Reluctance Machines (SRM) have recently received an increasing interest from the research community, insomuch as this converter has several advantages compared to other types of AC or DC machines, such as its greater efficiency, robustness, and mechanical simplicity. The magnetic design of the SRM includes salient poles at stator and rotor...

p>El presente trabajo trata sobre el estudio, diseño e implementación de un inversor multinivel capaz de operar con los esquemas de distribución eléctricos más comunes en el Ecuador y que pueda ser acoplado a la línea sin necesidad de transformador. Su control incluye la posibilidad de revertir los flujos de potencia en caso de ser necesaria la car...

Synchronous Reluctance (SynRel) machines are extensively used in high efficiency speed control applications. Magnetic saturation has an important effect on the dynamic performance of the SynRel machine. This phenomenon causes a non-linear relationship between the current and the magnetic flux linkage of each phase of the electromechanical converter...

In this paper the results of the dynamic model for a permanent magnet generator and its controller to be used on a wind turbine system are presented. The wind model is conceptually based on the behavior of the power extraction. The permanent magnet machine is modeled in the space vector coordinates using the rotor frame. The power converter realize...

This paper proposes an off-line method to determine the electrical parameters of an induction machine based on two instantaneous indicators (impedance and power). The method uses the induction machine start-up voltage and current measurements. Also, the proposed method employs a space vector dynamic model of the induction machine referred to the fi...

A predictive control scheme to control the phase currents of a three-phase power converter coupled to the electric grid by means of an LCL network is developed. This kind of coupling offers several advantages when compared to pure inductive coupling networks, namely a greater attenuation of switching harmonics and a smaller size. Equations that mod...

This paper proposes a control scheme for a wind turbine using a DFIG electromechanical converter, implemented through an NPC three-level back to back converter, that keeps a unitary power factor injection to the grid and maximizes the energy harvested from wind, using a maximum power point tracking algorithm (MPPT). A predictive direct power contro...

This paper presents the use of a training algorithm based on a Lyapunov function approach applied to a stator current controller based on a state variable description of the induction machine plus a reference model. The results obtained with the proposed controller are compared with a previously reported method based on a Nonlinear Auto-Regressive...

In this paper an active power filter is presented based on a multilevel converter. The active power filter is intended to be used in domestic applications where reactive power compensation in two-phase networks is required. An innovative technique to balance the DC bus voltages of the power converter capacitors is proposed and also an estimation al...

This work presents a comparison of three techniques for parameter estimation of the induction machine dynamic model. The first estimation method is based on measurements with the rotor at standstill while several single phase voltage sources are applied at different frequencies. The second method is based on obtaining the instantaneous measurements...

This paper investigates the use of fractional order PI α controllers, applied to inverter driven induction machines. Fractional order controllers provide additional degrees of freedom for their design, and the non-linearity introduced by the fractional part of the controller provides better tuning for the operation of the controller. In this work a...

This paper proposes a control scheme for a wind turbine using a DFIG electromechanical converter, implemented through an NPC three-level back to back converter, that keeps a unitary power factor injection to the grid and maximizes the energy harvested from wind, using a maximum power point tracking algorithm (MPPT). A predictive direct power contro...

This work presents three fuzzy variable structure control (FVSC) techniques applied to the current control loop in a three-phase synchronous rectifier. These techniques are based in a Takagi-Sugeno (T-S) fuzzy PI controller. The first controller is a first-order FVSC, used as a reference. Then, two FVSC strategies are presented and tested, a second...

This work presents the design and development of a three-phase multilevel hardware platform for applications in power electronics. The emphasis of the proposed converter is in its flexibility to allow rapid setups of different experiments typically required in power electronics teaching and research. The proposed converter uses a cascaded H-bridge...

This paper presents a predictive direct torque control PDTC algorithm for induction machine drives including a Sliding Horizon Prediction (SH-PDTC). The selected strategy for the SH-PDTC algorithm was to keep the motor torque and stator flux-linkage within predefined hysteresis bounds while reducing inverter switching losses. The proposed SH-PDTC alg...

This paper presents a general filtering and unbalance compensation scheme for electric traction systems using a direct power control-based algorithm. For a balanced three-phase three-wire system, the proposed method is able to control the power flow exchange between the grid and the load so that the instantaneous complex power is maintained constan...

This work proposes a model for induction machines in natural coordinates “abc”, developed considering the nonlinear characteristics of saturation. Traditionally, the models for the induction machine including this effect make use of linear transformations. However, the nonlinearity of saturation does not allow the use of these transformations, givi...

Parameter identification for the dynamic model of an induction motor is evaluated, taking into account the magnetic saturation curve. The identification scheme is based on a Particle Swarm Optimization algorithm to fit the motor and model startup stator currents curves. Two different strate-gies are compared. The first one adds the saturation effec...

This work presents a comparison between four control techniques applied to drive a PMSM: Classic DTC, Modified DTC with a Fuzzy Inference System, Predictive DTC and Predictive DTC with Fuzzy Inference System. Parameters estimation for the predictive strategies is performed using a population-based search algorithm (Bacterial Foraging), which is abl...

Resumen En este trabajo se comparan dos metodologías para la detección de cortocircuitos y fallas entre chapas de núcleos magnéticos, para lo cual se realizaron los ensayos sobre las cha-pas que conforman el estator de un motor de inducción, con el objetivo de determinar el método de detección más eficaz. Los méto-dos sometidos a comparación son: M...

This paper proposes a method that allows the operation with direct torque control under incipient faults of the power switching devices in single dc-link dual inverters. Once the fault onset of the switching device is detected, the troubled devices are put under trigger suppression to regain operation. The proposed control algorithm makes use of ad...

A breakdown of the electrical insulation system causes catastrophic failure of the electrical machine and brings large process downtime losses. Preventive maintenance and online monitoring are some of the methods to improve the reliability and to reduce unscheduled downtime. One of the main reasons for the failure of the machine is the breakdown of...

This paper presents a dual converter employed as a rectifier with power factor regulation and bidirectional power flow. The active and reactive powers flowing into the converter is controlled using an optimized direct-power-control algorithm. The multilevel structure of the converter is exploited to control the voltage level in each subconverter by...

This paper presents a generalized and compact space vector modulation algorithm valid for both (a, b, c) and (x, y) coordinates, suitable for triangle comparison modulators. The proposed algorithm uses a two base-vectors duty cycle computation by mapping the solution space into only three parallelogram shaped zones (Fig. A). This generalized algori...

In this work, the possibilities offered by the additional switching states present in an asymmetric three phase converter (compared with the existing states in the conventional three phase inverter) are studied in order to improve the performance of Direct Torque Control induction motor drives. The proposed algorithms make use of these additional s...

This work presents a filtering and unbalance compensation scheme for electric traction systems with open delta transformers using dual converters. The proposed method uses an active filter controlled with the instantaneous active and reactive power, to reduce the harmonic current distortion and the negative sequence present in the railway system un...

En este trabajo se realiza un estudio de la densidad de corriente dentro de un canal Magneto-Hidro-Dinámico (MHD) y su interacción con campos magnéticos. En el estudio se incluye la modificación de parámetros geométricos en el canal, para analizar su efecto sobre la distorsión de corriente, cuando se aplica un campo magnético. Entre los parámetros...

This work presents a general filtering and unbalance compensation scheme for electric traction systems. The proposed method uses an active filter controlled with the instantaneous active and reactive power, to reduce the harmonic current distortion and the negative sequence obtained by the system under unbalanced operation in steady state. The prop...

This work presents a dual converter employed as a rectifier with power factor regulation and bidirectional power flow. The active and reactive power flowing into the converter is controlled using an optimized direct power control algorithm. The multilevel structure of the converter is exploited to control the voltage level in each sub converter by...

This paper presents a parallelogram based duty cycle computation method for space vector modulation control using standard pulse width modulation circuitry. This technique maps the voltage source inverter’s solution space into only three parallelogram shaped zones and reduces the computational load. The proposed modulation methods are especially su...

La crisis actual del sector eléctrico venezolano es estructural. Durante varios años los especialistas alertaron a las autoridades sobre la necesidad de realizar las inversiones in- dispensables para el crecimiento del sector eléctrico, conocido y planificado por entes públicos y privados de gran prestigio y competencia. Cuando la desinversión se u...

A breakdown of the electrical insulation system causes catastrophic failure of the electrical machine and brings large process downtime losses. Preventive maintenance and online monitoring are some of the methods to improve reliability and reduce unscheduled downtime. One of the main reasons for failure is the breakdown of the stator insulation. Th...

In this work the application of additional switching states for the asymmetric converter is studied for its use in direct torque control. The proposed algorithm makes use of previously discarded states, that can increase the operational range of asymmetric converters by increasing the total number of switching states available for control. The prop...

In this work the ldquoBacterial Foragingrdquo strategy is presented and used to identify in real time a three-phase load. The optimization process uses the instantaneous current and voltage values as inputs, and estimates the values of the resistive and inductive parameters in the system. Simulations are used to verify the proposed strategy.

This work presents a filtering and unbalance compensation scheme for electric traction system with open delta transformers. The proposed method uses an active filter controlled with the instantaneous active and reactive power, to reduce the harmonic current distortion and the negative sequence obtained by the system under unbalanced operation in st...

This study presents an efficient control technique for computing the optimum space-vector voltage in power converters. The presented optimized direct power control (ODPC) provides a closed-form formula for the converter space-vector voltage, which, based on Lagrange operators for the optimum trajectory, provides the commanded complex apparent power...

Cuando se emplea un puente conversor asimétrico para alimentar un motor polifásico, cada devanado del motor se encuentra conectado de forma independiente al punto central de una de las columnas del puente conversor, aumentando la tolerancia del sistema a fallas de conmutación. En el caso trifásico, esta estructura conversora permite definir tres co...

A breakdown of the electrical insulation system causes catastrophic failure of the electrical machine and brings large process downtime losses. To determine the conditions of the stator insulation system of motor drive systems, various testing and monitoring methods have been developed. This paper presents an in-depth literature review of testing a...

When an Asymmetric Converter Bridge is used to drive a polyphase motor, each motor winding is independently connected to one converter's leg central point, increasing the system tolerance to commutation faults. In the three-phase case, this converter structure allows for the definition of three different sets composed by six non-zero voltage space...

Este trabajo presenta un estudio detallado del comportamiento del sistema eléctrico de tracción y su impacto sobre la operación de plantas de generación aislada. El sistema eléctrico y los generadores se modelan utilizando la teoría de vectores espaciales, lo cual permite un análisis detallado del comportamiento tanto en régimen transitorio como es...

En este trabajo se presenta el comportamiento de un motor de inducción manejado por un Puente Asimétrico, cuando se aplica uno de los cuatro posibles conjuntos de vectores para esta topología, denominado "de recuperación", para realizar el control de la máquina mediante la estrategia de Control Directo de Par. Los resultados, tanto simulados como e...

Este trabajo presenta las etapas de desarrollo y las mejoras posteriores del sistema de ensayo dinámico denominada «Plataforma», la cual es un equipo modular de prueba desarrollado por el Grupo de Sistemas Industriales y Electrónica de Potencia (GSIEP) de la Universidad Simón Bolívar en Caracas, Venezuela. Su finalidad es la realización de experime...

As the use of electric motors increases in the aerospace and transportation industries where operating conditions continuously change with time, fault detection in electric motors has been gaining importance. Motor diagnostics in a nonstationary environment is difficult and often needs sophisticated signal processing techniques. In recent times, a...

This paper proposes a wind speed estimation based sensorless maximum wind power tracking control for variable-speed wind turbine generators (WTGs). A specific design of the proposed control algorithm for a wind turbine equipped with a doubly fed induction generator (DFIG) is presented. The aerodynamic characteristics of the wind turbine are approxi...

This work presents a simple scheme for vector selection in Direct Power Control (DPC) in a three-phase rectifier without the use of switch selection tables, by using a rectifier voltage computed with a closed expression. The method is simulated using a C language description of the system and its results are later verified on an experimental test r...

This work presents the PLATAFORMA system impact over the teaching and research activities of the lecturers and the post graduate students at Master and Doctorate levels working in the Power Electronics Industrial Systems group (Grupo de Sistemas Industriales de Electronica de Potencia, SIEP) of the Universidad Simon Bolivar. PLATAFORMA is an integr...

This work presents the basic design of and later improvements to the integrated dynamic test system called Plataforma, which is a test rig developed by the Industrial Systems and Power Electronics Group (GSIEP) of the Universidad Simón Bolívar in Caracas, Venezuela. It is intended for experiments in power electronics and motor control, testing new...

A breakdown of the electrical insulation system causes catastrophic failure of the electrical machine and brings large process downtime losses. To determine the conditions of the stator insulation system of motor drive systems, various testing and monitoring methods have been developed. This paper presents an in-depth literature review of more than...

This paper shows a detailed study of the electric traction system behavior and its effect on the operation of isolated generation plants. The electrical system and its generators are modeled using the space vector theory, which simplifies both steady state and transient analysis. Commonly, electrified traction systems use Scott transformers in orde...

Since its development, permanent magnet synchronous machines (PMSM) has been used in a number of specific applications. However, in recent years PMSMs have become more attractive due to developments in new materials for permanent magnets and in semiconductor technology for converter design. Recent investigations have proposed some implementations a...