Papers by Ernesto Ruppert Filho
Journal of Physics: Conference Series, 2014
Resistive-type of superconducting fault current limiters (RSFCL) have been developed for medium v... more Resistive-type of superconducting fault current limiters (RSFCL) have been developed for medium voltage class aiming to operate at 1 MVA power capacity and short time recovery (< 2 s). A RSFCL in form of superconducting modular device was designed and constructed using 50 m-length of YBCO coated conductor tapes for operation under 1 kV / 1 kA and acting time of 0.1 s. In order to increase the acting time the RSFCL was combined with an air-core reactor in parallel to increase the fault limiting time up to 1 s. The tests determined the electrical and thermal characteristics of the combined resistive/inductive protection unit. The combined fault current limiter reached a limiting current of 583 A, corresponding to a limiting factor of 3.3 times within an acting time of up to 1 s.
IEEJ Transactions on Industry Applications, 1996
An electrical and thermal mathematical dynamic model for a three-phase squirrel-cage induction mo... more An electrical and thermal mathematical dynamic model for a three-phase squirrel-cage induction motor is described to evaluate, via microcomputer, stator winding, rotor winding, stator core and rotor core instantaneous temperature rises for motors operating fed from sinusoidal and nonsinusoidal (inverter) voltage power supplies and driving continuous and intermittent load duties, including startings and brakings. It is required regular manufacturer bulletin data and also stator core, stator winding, rotor core and rotor winding masses. The model takes into account the skin effect on rotor parameters and the changings of the winding electrical resistances with the respective machine part temperatures.
Energies
In this article the improved sampled average modulation technique is proposed, this technique has... more In this article the improved sampled average modulation technique is proposed, this technique has 2N + 1 levels in the output voltage waveform of MMC and it is considered as of low complexity of implementation for any number of submodules per arm. For that, characteristics such as dynamic response, implementation complexity, inverter output voltage waveform levels, and switching frequency are considered to evaluate and validate the proposed modulation technique. The proposed technique is compared with other three previously proposed techniques, its considering parameters such as the THD and the fundamental value of the output voltage, and also the peak-to-peak variation of the submodule capacitor voltage. Several simulations were performed in the Matlab/Simulink software and with these results, it was validated the proposed modulation technique, and also it is verified that the proposed technique is computationally more efficient. This last one shows its potential for multiphase mul...
Renewable energy systems and specially wind energy have attracted governmental interests in oppos... more Renewable energy systems and specially wind energy have attracted governmental interests in opposition to energy sources that increase CO2 emissions and cause enormous environmental impact. Recently, the concept of smart grid has been applied to power plants to enable and optimize the generation of energy by efficiently combining wind, solar and tidal. Moreover, the efforts for consolidation and implementation of this new concept through wind energy systems have attracted great interest from the technical community and has been the focus of several recent scientific works [1–3].
Renewable Energy and Power Quality Journal, 2010
This paper proposes a direct power control scheme for doubly-fed induction generator for variable... more This paper proposes a direct power control scheme for doubly-fed induction generator for variable speed wind power generation. Using a stator flux decoupling and deadbeat control loops the algorithm calculates the rotor voltage vector to be supplied to the rotor in order to eliminate the active and reactive power errors that can achieve high accuracy and fast dynamic power response based on the estimated stator flux, the active and reactive power and their errors. Simulations results are carried out for validation of the digital controller operation.
Anais do Simpósio Brasileiro de Sistemas Elétricos 2020, 2020
Neste artigo é proposta uma nova técnica de modulação baseada na teoria de vetores espaciais para... more Neste artigo é proposta uma nova técnica de modulação baseada na teoria de vetores espaciais para o conversor modular multinível. Essa técnica emprega um algoritmo de seleção com 4 pontos de referência para obter a sequência padrão de pulso das tensões trifásicas do braço superior e inferior em uma frequência de comutação reduzida. Essa técnica opera em uma frequência de comutação baixa e gera N +1 níveis na forma de onda de saída do inversor e tem uma baixa ondulação na tensão dos capacitores dos submódulos e também, ée adaptada para ser compatível com o algoritmo de classificação para equilibrar a tensão de cada capacitor do submódulo do braço do conversor. A técnica proposta possui quatro etapas principais que são apresentadas em detalhe.
A three-phase induction motor direct torque control laboratory setup for simulation and experimen... more A three-phase induction motor direct torque control laboratory setup for simulation and experimental activities is presented in this paper. It includes sliding-mode controllers and uses a sensorless method to estimate rotor speed. The objective of this setup is to present to the students a simulation tool based on Matlab SimPowerSystems toolbox with the possibility to check simulation results against a DSP based experimental system. The setup provides to the electrical engineering students an excellent learning tool for nonlinear control studies using as example the variable speed three-phase induction motor control. Linear control systems are extensively studied in electrical and computer engineering theoretical and experimental sessions while non-linear control systems aren't.
Eletrônica de Potência, 2011
A deadbeat power control scheme for doubly-fed induction generator for variable speed was propose... more A deadbeat power control scheme for doubly-fed induction generator for variable speed was proposed. The deadbeat controller algorithm calculates the voltage vector to be supplied to the rotor in order to eliminate the active and reactive power errors in each period using and stator field orientation and the doublyfed induction generator dynamic model. The deadbeat controller uses the rotor current control to the power control of the machine. This control technique can be applied to the wind energy systems. Experimental results are carried out to validate of the deadbeat controller operation.
Eletrônica de Potência, Jun 1, 2005
This paper presents a four-wire shunt active power filter fully controlled with neural networks. ... more This paper presents a four-wire shunt active power filter fully controlled with neural networks. The paper is centered on a current compensation method based on adaptive linear elements (adalines), which are powerful and easy-to-use neural networks. The reader will find here an introduction about these networks, an explanatory section about the achievement of Fourier series with adalines, and the full description of an adaline-based selective current compensator. The paper also brings a discussion about the use of a feedforward neural network in the current controller of the active filter, as well as simulation and experimental results obtained with a prototype of a shunt active power filter.
Eletrônica de Potência, 2013
This article proposes a Direct Vector Control (DVC) method with a Fuzzy Logic Current Controller ... more This article proposes a Direct Vector Control (DVC) method with a Fuzzy Logic Current Controller (FLCC) for three-phase induction motor. The conventional DVC method has two PI current controllers. With the aim to reduce the quantity of these controllers, we propose a single FLCC to substitute both PI controllers. The FLCC calculates the quadrature components of the stator voltage vector which are necessary to maintain the load. The rule base for the proposed controller is defined as a function of the stator current error components, and FLCC utilizes trapezoidal and triangular membership functions for the fuzzification of its inputs. The switching frequency is constant with the space vector modulation technique used in the DVC method. The performance of the proposed FLCC controller is analyzed through several tests such as: trapezoidal and triangular speed profile, step change in speed and step change in load with constant speed. The simulation and experimental results show that the proposed FLCC ensures decoupling current control and low current ripple, validating the proposed controller.
Eletrônica de Potência, 2014
This paper proposes a decoupled control of active and reactive power for doubly-fed induction gen... more This paper proposes a decoupled control of active and reactive power for doubly-fed induction generators (DFIG) by using the rotor current control loop and sliding mode control (SMC). In order to decouple the active and reactive power generated, stator-fluxoriented vector control is applied. The sliding mode control strategy proposes is based on two sliding modes plus PI controllers whose main advantage is the easy implementation. Simulation and experimental results are presented to validate the proposed control scheme for a 2 kW DFIG during stator active and reactive power steps and rotor speed variation. During transient operation it is checked good dynamic response.
Eletrônica de Potência, 2017
Resumo-Neste trabalho descreve-se uma nova proposta de um sistema de geração eólica que controla ... more Resumo-Neste trabalho descreve-se uma nova proposta de um sistema de geração eólica que controla as potências ativa e reativa e realiza a função de filtragem ativa das componentes harmônicas de correntes da rede elétrica. A compensação harmônica é realizada por um algoritmo aplicado ao conversor do lado da rede elétrica na presença de uma carga trifásica não linear no ponto de acoplamento comum. Esta técnica quando empregada de modo correto melhora a qualidade de energia. O conversor do lado da máquina controla as potências ativa e reativa que são entregues à rede através do controle vetorial por orientação de fluxo do estator. Uma metodologia de projeto dos controladores utilizados nessas técnicas propostas é apresentada. Resultados de simulações e experimentais confirmaram a eficácia e desempenho do sistema proposto.
Renewable Energy and Power Quality Journal, 2015
This work presents the analysis of harmonic of 5th and 7th orders impacts in the grid voltage in ... more This work presents the analysis of harmonic of 5th and 7th orders impacts in the grid voltage in a wind generation system based on DFIG. Therefore, there were simulations of the active and reactive power control of the DFIG using the vector control by orientation of the magnetic stator flux. The results of three simulations are presented. In the first simulation it is presented the analysis of the wind power generation system connected to an electric grid with purely sinusoidal voltage. In the second simulation, the wind generation system is connected to an electric grid with distorted voltage for 5th and 7th harmonic orders. In the third simulation it is shown the results of the reduction of harmonic distortion in the electrical currents at the PCC and at the output of the electronic power converter by applying notch filters in the converter current control loops connected to electrical grid.
Renewable Energy and Power Quality Journal, 2015
One of the basics characteristics of a power electric system is guarantee the power supply to the... more One of the basics characteristics of a power electric system is guarantee the power supply to the loads reliable and uninterrupted, the modern power systems have minimal conditions for proper operation, one of studies of major concern is stability. The studies most considering the electric power system as a whole, taking into account elements that affect their behavior, mainly including the dynamic model of the loads. Within industrial environments loads are formed by three phase induction motors, these loads must be modeled dynamically in detail to be possible a faithful study of the system and its real influence into the power system. Will be made dynamic tests into am industrial electric power system selected to verify the influence of induction motor loads, the motors also are controlled with DTC technique and the system can operate with internal generation. I.
IEEE Transactions on Power Electronics, 2017
This paper presents a complete approach for switched reluctance generator (SRG) in variable wind ... more This paper presents a complete approach for switched reluctance generator (SRG) in variable wind energy conversion systems. Two forms of direct power control (DPC) and a commutative system that allows SRG performance at a wide range of speed variations are proposed. Thus, more mechanical energy can be captured in wind generation. In the proposed structure, the SRG operates in a self-excited mode using a common dc bus system of a voltage source inverter connected to an electrical grid. DPCs are proposed by hysteresis of the SRG phase current for low-speed operation (DPC-LS) and by a single pulse of current for high-speed operation (DPC-HS). The low-pass filter employed to obtain the average power generated may slow down the response of the control system of the DPC applied to SRG. To improve the system performance, sliding mode controllers in DPCs were used. For operation throughout a wide speed range, the DPC-LS and DPC-HS controls should be joined. Therefore, a commutative system with smooth transition between DPC modes is proposed. Finally, simulations and experimental tests were conducted to verify the behavior of the proposed arrangement. The results confirmed correct operation of the proposed system. Index Terms-Direct power controls (DPCs), sliding mode (SM) controllers, switched reluctance generators (SRG), variable speed operation, wind energy. I. INTRODUCTION T HE switched reluctance generator (SRG) has been suggested as a good alternative for applications in wind power Manuscript
Sba: Controle & Automação Sociedade Brasileira de Automatica, 2012
A proposta deste trabalho é apresentar uma nova metodologia para determinação experimental das ca... more A proposta deste trabalho é apresentar uma nova metodologia para determinação experimental das capacitancias parasitas do motor de indução trifásico de rotor em gaiola. As capacitancias parasitas fazem parte do circuito equivalente do motor para estudos de interferência eletromagnética causada no motor de indução em modo comum quando ele for acionado por inversor controlado por modulação por largura de pulsos (MLP). Os procedimentos propostos para o desenvolvimento deste novo método consistem em: a) determinação dos parâmetros do circuito equivalente do motor de indução trifásico, em regime permanente, através de ensaio em laboratório; b) estabelecer configurações de ligações entre o inversor MLP e o motor para medições das grandezas de interesse que são as seguintes: tensões de modo comum e de eixo, correntes de fuga e de eixo, através de circuito de medição desenvolvido para este fim; c) calcular os valores das capacitancias parasitas entre estator e carcaça do motor; estator e ro...
Sba: Controle & Automação Sociedade Brasileira de Automatica, 2010
Com o avanço da tecnologia dos dispositivos semicondutores de potência os inversores de frequênci... more Com o avanço da tecnologia dos dispositivos semicondutores de potência os inversores de frequência atuam de forma importante em toda indústria. O inversor de frequência convencional contém elementos armazenadores de energia no seu elo de corrente contínua. Estes elementos armazenadores de energia são capacitores eletrolíticos e possibilitam manter a tensão do elo de corrente contínua constante. Entretanto, quanto maior sua capacitância maior é a distorção da corrente de entrada. Com a substituição do banco de capacitores eletrolíticos por um capacitor de filme, diminui-se a distorção nas correntes de entrada, porém distorções indesejadas aparecem na tensão do elo de corrente contínua e também nas correntes de saída. Estas distorções são compostas por componentes harmônicas de baixas frequências. O conversor em matriz trifásico-trifásico por sua vez, possibilita a transferência direta de energia da entrada (rede) diretamente para a saída (carga) sem a necessidade de elementos armazen...
In this article is proposed the Direct Torque Control (DTC) with Space Vector Modulation (SVM) ba... more In this article is proposed the Direct Torque Control (DTC) with Space Vector Modulation (SVM) based on Self-Tuning PI-Type Fuzzy (STPIF) controller. This controller determines dynamically the load angle between stator and rotor flux vectors and in consequence the electromagnetic torque necessary to supply the motor load. The rule base for STPIF controller is defined in function of the error and the change of the error of the torque using a most natural and unbiased membership functions (MF). Constant switching frequency and low torque ripple are obtained using SVM. Performance of the proposed DTC-SVM with STPIF are compared with the performance of the same scheme but using PI controller in terms of several performance measures such as settling time, rise time and integral-of-time multiplied by the absolute magnitude of the error index (ITAE). The simulation results show that the proposed scheme can ensure fast torque response and low torque ripple in comparison with DTC-SVM with PI controller.
This paper proposes a decoupled control of active and reactive power for doubly-fed induction gen... more This paper proposes a decoupled control of active and reactive power for doubly-fed induction generators (DFIG) through the rotor currents using sliding mode control (SMC). In order to decouple the active and reactive power generated, stator-ux-oriented vector control is applied. The sliding mode control strategy proposes is based on two sliding modes plus PI controllers whose main advantage is the easy implementation. Simulation and experimental results are presented to validate the proposed control scheme for a 2 kW DFIG during stator active and reactive power steps and speed variation. During transient operation it is checked good dynamic response. Streszczenie. W artykule opisano sterowanie moc a czynn a i biern a w podwójnie zasilanym generatorze indukcyjnym DFIG za pośrednictwem pr adu wirnika z wykorzystaniem metodyślizgowej SMC. Zastosowano sterowanie wektora strumienia stojana. Symulacje i badania eksperymentalne potwierdzi y za zenia mo zliwości sterowania systemem DGFIG 2 KW przy ró znych pr edkościach. Badano tak ze w aściwości dynamiczne. (Rozsprz e zone sterowanie moc a w generatorze DFIG przy wykorzystaniu metodyślizgowej)
This work proposes a direct torque control with space vector modulation based on load angle using... more This work proposes a direct torque control with space vector modulation based on load angle using PI controllers. This controller calculates dynamically the load angle between stator and rotor flux vectors using a PI controller. A reference of stator flux on stationary reference frame is calculated by using the load angle, rotor position and the stator flux magnitude. Another PI controller calculates the stator voltage to be supplied to the induction motor based on stator flux error. Thus, the electromagnetic torque necessary to supply the motor load is achieved. This strategy is easy to implement and experimental results are presented to validate the proposed strategy. Streszczenie. W artykule opisano bezpośrednie sterowanie momentem z przestrzenną modulacja wektora bazującą na kącie obciążenia i regulatorze PI. Sterownik dynamicznie oblicza kąt między wektorami strumienia stojana i wirnika. Ta strategia jest łatwa do zastosowania co potwierdziły wyniki eksperymentu. (Bezpośrednie sterowanie momentem trójfazowego silnika indukcyjnego bazujące na obliczaniu kąta obciążenia)
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Papers by Ernesto Ruppert Filho