N. M. Salgado-Herrera

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.

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.

Current-Sensorless VSC-PFC Rectifier Control With Enhance Response to Dynamic and Sag Conditions Using a Single PI Loop

This paper presents the design, modeling, implementation, and experimental results of an advanced current-sensorless control scheme for voltage source converter–power factor correction rectifiers. This proposal is aimed to reduce the complexity of the control while maintaining desirable features for ac/dc conversion, such as unity power factor, low total harmonic distortion in input current, continuous regulation of the dc voltage even facing ac voltage sags and dynamic load changes. Unlike other proposals, this scheme has a single feedback proportional-integral loop, uses few mathematical operations, and the dq0 reference frame is not included in the control scheme. These characteristics simplify the implementation of the proposed control thus improving its efficiency. The theoretical analysis and simulation validate the technical feasibility of the proposed control, and finally, various cases of study and experimental results obtained with a laboratory scale-down prototype are presented to confirm the viability and performance of the control.

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.

Step-up Transformerless Seven-level DC-AC Hybrid Topology for Interconnection of Renewable-based DC Sources to Microgrids

Abstract This article introduces a new step-up transformerless multi-level DC-AC hybrid topology for interconnecting renewable DC sources to loads or microgrids. This enabling technology incorporates the best characteristics of three modified basic topologies—a DC-DC multi-level boost converter, a DC-DC multi-level buck converter, and an H-bridge—to obtain a seven-level step-up DC-AC hybrid structure using only one DC input and nine power switches for a single-phase output with field-programmable gate array based control. The advantages of the step-up seven-level structure compared to other proposals are higher efficiency, a reduced number of power switches, and high power density associated with transformerless characteristic. Furthermore, in contrast to conventional topologies, the proposed design does not require voltage/current monitoring of the capacitors or a capacitor-balancing control scheme, and only one DC source input is used. Consequently, a high-performance configuration is obtained. The laboratory results demonstrate the validity of the design and the performance of the prototype.