Improved virtual flux direct power control of three phase PWM rectifier using SOGI-FLL estimator under disturbed voltage conditions

Abstract

In this paper, improved sonsorless direct power control (DPC) of three-phase rectifiers is presented. The new system are based on virtual flux (VF) and notch filter using Second Order Generalized Integrator frequency located loop SOGI-FLL estimator. In order to improve the VF-DPC performance of PWM rectifier, an improved observation method of virtual flux-linkage is proposed. To avoid the relevant problems of pure integrator, and to achieve the accurate observation of the grid voltage’s phase, (SOGI-FLL) are used to displace the pure integrator. Theoretical principles of this method are presented and discussed. These strategies are also investigated under disturbed grid voltage. A theoretical analysis of active and reactive power under a non-ideal source is clearly demonstrated. In order to calculate the compensated powers, the extraction of positive, negative, and harmonic sequences of voltage and current is needed and a multiple dual SOGI-FLL method is used for rapid and accurate extraction. It is shown that the VFDPC with integrating notch filter exhibits several advantages, particularly providing small ripple of DC-link voltage and sinusoidal line current when the supply voltage is not ideal.

Overall fuzzy logic control strategy of direct driven PMSG wind turbine connected to grid

“…The block diagram of the electrical and mechanical model is presented in Figure 2. In order to control the power produced by the PMSG wind turbine and improve its quality, various converter topologies can be selected according to load types, system size and economic criteria [15]. IGBT-based buck-to-buck rectifier-inverter owns a flexible structure for different control methods and can be used to adjust the generator speed and control the power injected into a utility grid.…”

“…PWM rectifier/inverter is made using the IGBT transistors as switchable semiconductors. These devices offer the advantages stated in [15]. Several control strategies have been proposed in recent works such as: Hysteresis PWM, Periodic sampling PWM, Sine-triangular PWM and space-vector modulation (SVM).…”

Sensorless Direct Power Control for Three-Phase Grid Side Converter Integrated Into Wind Turbine System Under Disturbed Grid Voltages

“…The global magnitude of total harmonic distortion (THD) presented by VF-DPC and the resilient direct power control RV-DPC is always inferior to that of V-DPC [15]. The V-DPC possesses a low immunity to asymmetric and deformed voltage; the VF-DPC shows a better reliability only under distorted grid voltage [15] a new method of VF-DPC control based on the virtual flux estimate Capable of handling these problems; it results in a stable and regular estimated virtual flux with a sectorial detection at a high precision [23].…”

New control scheme for synchronizationof a photovoltaic system to a three-phase grid to attenuate the harmonics of currents caused by distorted grid voltage

“…The capacity of the photovoltaic power stations increases considerably because of the low cost installation, Thus, it is necessary to develop new control strategies for the operation and control management of the PV system's integrated to the grid so that improving the quality, the energy efficiency and the reliability of the system [11,12]. The grid voltage parameters, such as frequency, phase angle, and amplitude are important information for many areas of electrical system applications, as the supply converters connected to the grid [13,14]. The inverters dedicated to photovoltaic systems have to respond rapidly in milliseconds because of the variation of solar irradiation [15].…”