Aurelio Medina-Rios

Reactive power regulation and voltage compensation through DSTATCOM with wind turbine integration

Wind generation is a promising source of electrical energy. It used to supply of electrical energy to cities or heavy loads. However, the supplied voltage should be of practically constant voltage profile. An induction generator directly connected to the network is used to represent a wind power generation system. When the active power supplied by an induction generator is varied with the wind, the reactive power absorbed and the induction generator output voltage are affected. DSTATCOM provides voltage stability to power systems, due to its ability to generate or absorb reactive power. This paper reports a model representation and results obtained from the application of a DSTATCOM used to compensate voltage and reactive power in electrical networks with wind turbines integration.

Periodic steady state determination of power systems using graphics processing units

Modern advances in computer technology will definitely have a great impact on the methodologies used in the expansion and operational planning of power systems. Parallel and distributed systems are the new tendencies in technologies that present a great potential for application in these areas. Graphics processing units (GPUs) have recently become popular in several fields of science due to their capability of performing massively large computational tasks. The use of a GPU for efficiently obtaining the periodic steady state solution in the time domain of large-scale electric power systems with nonlinear components is presented in this paper. Two programming models of the numerical differentiation process are proposed and implemented on a single GPU. The computation time of the simulation performed by co-processing GPU-CPU has been compared with the simulation time required when using a conventional CPU. Several test cases have been analyzed to demonstrate the acceleration of the GPU-CPU simulation and the speed-up achieved.

Solar cell model: a bond graph approach

A solar cell model that combines the photovoltaic and electro-thermal processes is proposed. The bond graph methodology is used as a reference frame, allowing the representation of the whole structure in a unified approach. The solar cell structure is modeled as a three-dimensional object allowing observation of a nonuniform solar radiation on the surface. Subsequently, the proposed model is used in the solar cell design.

THD mitigation in type-4 Wind Turbine through AFE Back to back converter

In wind power generation systems the type-4 Wind Turbine (WT) is the best option for future research, since WT is completely isolated from AC network through Back to back converter. Hence, full scale back to back is required for high power operation. Total Harmonic Distortion (THD) generated on AC grid by WT is depending of back to back converter switching frequency. In this paper, an AFE back to back converter to transfer high power when m VSCs are placed in parallel is developed, with significant THD reduction through SPWM techniques.

Selective harmonic current mitigation with a Shunt Active Power Filter

This paper proposes a Shunt Active Power Filter (SAPF) for harmonic mitigation based a selective harmonic current mitigation (SHCM) method. The proposed SHCM method improves the filtering efficiency and solves many issues existing in highly contaminated loads. The Fast Fourier Transform (FFT) is applied to a specific harmonic current detection of a three-phase circuit. A simulation study of a three-phase compensated system is carried out using Matlab/Simulink® to validate the proposed method.

Reactive power compensation in distributed networks with wind turbine integration using resonant corrector

In this paper, the control of a Distribution Static Synchronous Compensator (DSTATCOM) based on Resonant Corrector (RC) is proposed, for the reactive power compensation of a distribution network with wind turbine (WT) integration. The sinusoidal system transformation to the dq0 reference frame is usually made, in order to model Proportional + Integral (PI) controllers. However, these controllers are unable to completely remove voltage unbalance transients during the power interchange between the distribution network and the WT. The use of a Resonant Corrector (RC) for compensating voltage disturbances allows developing the control in the abc reference frame; thus, it is not necessary the use of a Phase Lock Loop (PLL) and the system with the minimum of components is managed, generating a sensorless control, working reliably in steady state and under unbalanced transient operation conditions. The distribution network through MATLAB & Simulink® is simulated.

Reactive Power Compensation in Wind Energy Systems through Resonant Corrector in Distributed Static Compensator

Abstract This paper proposes a resonant corrector-based control for the distributed static compensator (DSTATCOM) to compensate voltage and reactive power in a wind energy system (WES). The sinusoidal system transformation to the dq0 reference frame is usually made in order to model proportional-integral (PI) controllers in three-phase power systems. Nevertheless, PI controllers cannot remove completely voltage transients, generating amplitude, and phase voltage errors in the WES response. However, voltage and reactive power compensation in the abc reference frame can be achieved using a DSTATCOM through a resonant corrector. The introduced control law allows the WES to work reliably without magnitude and phase errors, in steady state and under unbalanced transient conditions. The proposed control law is validated through simulations with MATLAB - Simulink® (Natick, Massachussetts, USA) and experimental laboratory tests using the concept of rapid control prototyping and the real-time simulator Opal-RT® Technologies (Montreal, QC, Canada).

Reactive power compensation through active back to back converter in type-4 wind turbine

In this paper, the mathematical model of type-4 wind turbine topology is developed to represent its dynamic behavior. The main objective of a type-4 wind turbine is to deliver active power to the system, but to perform this action; it must absorb reactive power from the power network, causing disturbances and stress in the rest of the power system. Through the dynamic control system used in the back to back converter, the reactive power compensation at the PCC is achieved, making possible the energy exchange between the type-4 wind turbine and the rest of the power network.

Periodic steady state solution of power systems by selective transition matrix identification and graphic processing units

Modern power systems analysis becomes more challenging due to their increasing complexity, greater interConnectivity of elements and sub-systems and the use of alternative generation systems, among others. In order to efficiently conduct these analyses, it is necessary the use of modern computational and numerical techniques, such as parallel processing and fast periodic steady state solution techniques. The Numerical Differentiation (ND) method has been successfully applied to meet the last issue. This paper introduces a modification to the ND method using GPUs, which allows a significant reduction on the computation time required to reach the steady state solution in nonlinear power systems.