A 3-Ф grid connected wind system with a technique of DC link control using fewer sensors with fuzzy controller

PurposeThis paper aims to provide a permanent magnet synchronous generator (PMSG) wind turbine, which feeds electric power (AC) to the power grid. The converter, located on the machine side, is used to produce the full amount of wind power. Research on wind energy conversion system (WECS) is carried out in this study using a direct wind turbine in MATLAB with constant and variable speeds.Design/methodology/approachThis paper is about WECS using PMSG and is connected to a grid of two serial converters with common DC connections.FindingsThis paper aims to provide the value of DC connection voltage at its base, regardless of the wind speed alterations, the inverter's output ac voltage can be kept constant.Originality/valueThis paper aims to provide a Hill Climb Search maximum power point tracking (MPPT) algorithm is an effective control system for extracting maximum energy, also called voltage control, pitch control, phase-locked loop (PLL) controls, from a wind turbine. Using the Fuzzy controller, the grid side converter is controlled.

Intensifications reactive power during of asymmetric network outages in dual-stator winding generators

<span lang="EN-US">The paper proposes a protection to dual stator generator, reluctance rotor, from asymmetrical fault. Which prevents the dual stator generator, reluctance rotor, from electrical sage through working process in order to avoid any interruption in the generator-grid connection. The procedure consummated with injecting suitable reactive power during the fault period. The proposed method that makes it possible for wind turbine application via dual stator winding generators (DSWRG) synchronous mod to stay connected to the grid during asymmetrical faults. It has been built according to trusted simulating mode considering all tested parameters according to experiment work. The expirment, consider the DC link side stability and care about the behavior and performance of machine side parameter. As well the machineability is evaluated to ride through asymmetrical fault by observing the secondary side current which has a big role in saving grid side converter. The control takes a response within 200 ms after fault trigger recognition. The generator ability of dynamically remaining connected stable and existing in the network, which is sustained a series voltage disturbance by injecting appropriate amount of reactive power. The main interest required in this paper is the capability of a machine to overcome the asymmetrical fault.</span>

Research on additional damping control of sub-synchronous oscillation in series-compensated DFIG system

Since series-compensated grid-connected system of doubly fed induction generator (DFIG) may cause sub-synchronous oscillation, with the purpose of improving the system stability, in this paper, the mechanism of sub-synchronous oscillation (SSO) is analyzed from the perspective of system damping, according to the mechanism, an additional damping controller is designed to suppress SSO. The controller uses rotor speed as the input signal and adds it into the d-axis current inner loop of the grid-side converter through filtering and proportional amplification, with the purpose of providing positive damping to the system. Finally, the model of DFIG series-compensated grid-connected system is established on PSCAD/EMTDC simulation platform to verify the suppression effect of the additional damping controller through time-domain simulation. The simulation results show that the device has good respond speed and suppression effect.

Generator and grid side converter control for wind energy conversion system

<p>This paper focuses on the modeling and control of a wind energy conversion chain using a permanent magnet synchronous machine. This system behaves a turbine, a generator, DC/DC and DC/AC power converters. These are connected on both sides to the DC bus, where the inverter is followed by a filter which is connected to the grid. In this paper, we have been used two types of controllers. For the stator side converter, we consider the Takagi-Sugeno approach where the parameters of controller have been computed by the theory of linear matrix inequalities. The stability synthesis has been checked using the Lyapunov theory. According to the grid side converter, the proportional integral controller is exploited to keep a constant voltage on the DC bus and control both types of powers. The simulation results demonstrate the robustness of the approach used.</p>

Application of DPC and DPC-GA to the dual-rotor wind turbine system with DFIG

<p>The work presents the dual-rotor wind energy conversion system (DRWECS) with a direct driven doubly-fed induction generator (DFIG). The system consists of a dual-rotor wind turbine (DRWT) with a DFIG, the grid side converter (GSC), and the machine side converter (MSC). To command the MSC, the direct power command (DPC) based on genetic algorithm (GA) and classical pulse width modulation (PWM) has been applied. To achieve the maximum power from the DRWT, the maximum powe point tracking (MPPT) technique has been used. The performed simulation studies confirmed the high performances of the DPC-GA contro method.</p>

Harmonics Reduction and Reactive Power Injection in Wind Generation Systems

In this work, methods are implemented to improve two aspects of energy quality in a wind generation system. First, the harmonic reduction is achieved by applying a linear control technique in the Grid Side Converter; and second, the power factor of the wind generation system using a Doubly Fed Induction Generator (DFIG) is adjusted by injecting reactive power. The reduction of the harmonic content is performed with a digital resonant controller, which tracks the periodic signals corresponding to the current harmonics of the Grid Side Converter (GSC), which is part of a “back to back” converter in a wind generation system. This technique allows implementing a current controller of the GSC with a high level of rejection of current harmonics, of frequencies with orders (1 + 6k) and (1 − 6k) (where k is an integer), when executed in the synchronous reference frame (dq). The purpose of this work is to inject currents to the grid with very low harmonic distortion and provide a method for tuning the resonant controller for a simple L filter; also, the GSC is used to generate reactive power. These two improvements achieve a unity power factor, and this is necessary to comply with the new codes where a leading power factor helps regulate the grid voltage.