Federico M. Serra

Comparison of positive sequence detectors for shunt active filter control

The influence of using different methods to detect the positive sequence of the grid voltage fundamental component on shunt active filter control is analyzed in this work. Three kind of positive sequence detectors are considered: detectors based on the pq Teory, EPLL-based detectors and those based on SOGI. Shunt active filter behavior is analyzed through simulation results using each one of these positive sequence detectors on balanced grid voltage, unbalanced grid voltage and unbalanced and distorted grid voltage conditions.

Non-linear control of a three-phase front end converter

The design of a non-linear controller for a three-phase front end converter used to connect renewable energy sources to the grid is presented in this paper. The objectives of this controller are the injection of all the generated power into the grid and the control of the reactive power exchanged with the power system. The system is represented through Park coordinates and port controlled Hamiltonian models. The controller is designed by interconnection and damping assignment (IDA), and feedback linearization (FL). It is demonstrated that for the particular case of selecting interconnection and damping matrixes, then coupling can be eliminated from the system model and therefore the controller designed using interconnection and damping assignment results the same as that using feedback linearization. The control strategy proposed in the present work is validated through simulation.

Application of the modified IDA‐PBC for shunt active power filters control

Summary The design of a passivity-based nonlinear controller for a shunt active power filter to be used for the compensation of harmonic currents consumed by nonlinear loads is presented in this paper. The main objective of designed controller is to inject the necessary compensation current into the system so that the grid current is sinusoidal and balanced, regardless of whether the grid voltage is unbalanced and/or distorted. The references for the compensation currents are obtained from applying the pq theory. The controller is designed on the basis of a modified interconnection and damping assignment technique, which allows solving a tracking control problem. An integral action controller is added to the proposed controller using the same design technique, in order to eliminate the errors produced by parameter variations or uncertainties. The behavior of the proposed control strategy is validated through simulation using a realistic model, which includes converter switching and losses, grid distortion, and parameter variations. Copyright

Passivity Based Control of a Three-Phase Front End Converter

A new controller aimed to regulate voltage and frequency of a Front-End Converter used in stand-alone wind generation systems is proposed. Control objective is to maintain the output voltage with constant amplitude and frequency, independently of the load supplied. Controller is designed using the Interconnection and Damping Assignment technique. System stability is ensured through a proper choice of the energy function of the system in closed-loop. The behavior of the proposed control strategy is validated through simulations using a realistic converter model.

Passivity-based control of a three-phase Front End Converter for stand alone wind generation system

A new controller aimed to regulate voltage and frequency of a Front-End Converter used in stand-alone wind generation systems is proposed. Control objective is to maintain the output voltage with constant amplitude and frequency, independently of the load supplied. Controller is designed using the Interconnection and Damping Assignment technique. System stability is ensured through a proper choice of the energy function of the system in closed-loop. The behavior of the proposed control strategy is validated through simulations using a realistic converter model.

Implementation and Control of a Magnetic Levitation System

A magnetic levitation control system is developed in this work. The non-linear system model is linearized around the operating point. Two control loops, an inner current loop and an outer position loop are designed using the linear system obtained. The hardware implementation is described. Simulation and experimental results are shown to validate the dynamic response of proposed control.

Experimental implementation of PSDs

A comparison of different methods used to detect the fundamental positive sequence component of grid voltage, is analyzed in this work. These detection methods are necessary to achieve proper synchronization between generation systems, based on renewable energy, and the grid where this systems are connected. Two different structures commonly used as positive sequence detectors based on PLL are analyzed: SOGI and q-PLL. The performance of the detectors is tested in simulation, in continuous and discrete time. A experimental implementation of the detectors in a floating point DSP is realized. Different discretization methods of integrators is analyzed. Experimental results validate detection methods presented.

IDA-PBC control of a single-phase battery charger for electric vehicles with unity power factor

A passivity based control strategy for an electric vehicle single-phase battery charger is presented in this paper. The proposed control strategy allows charging the battery bank with constant current and constant voltage charging profile, while ensuring unity power factor and low distortion in the grid current. The battery charger system consists of two converters whose controllers are designed using interconnection and damping assignment. In order to avoid distortion in the grid current while achieving a fast control of the DC-Link voltage, a trajectory-tracking controller, both for the grid current and the DC-Link voltage is proposed. With this aim, a variable reference signal of the DC-Link voltage is computed using the information of the power required by the battery and the grid power. The proposed control strategy ensures the closed-loop stability and allows decoupling the system to simplify the calculation of the controller parameters. The proposal is validated with simulation results.

Estrategia de control para la gestión de la energía en un sistema híbrido aislado

An energy management control strategy for an isolated hybrid system is presented in this paper. The system consists in a photovoltaic panel connected to a boost converter and an auxiliary battery powered by a bidirectional Buck-Boost converter. The purpose of this control strategy is to keep the DC-Link voltage on a reference value under load variations and changes in the panel conditions. The proposal is validated with simulation and experimental results.

Control strategy for an electric vehicle battery charger with unity power factor

A nonlinear control strategy for an electric vehicle battery charger is presented in this paper. The proposed control allows charging the battery bank with constant current and constant voltage charge profile, while ensuring unity power factor and low distortion in the grid current. Control strategy is designed using interconnection and damping assignment from a unique model of the complete system. This control strategy ensures the closed-loop stability and allows decoupling the system avoiding that the grid disturbances affect the charge of the battery and vice-versa. The proposal is validated with simulation results.