Second-order Generalized Integrator Phase-locked Loop Research Articles

Robust Normalized Mixed-Norm Adaptive Control Scheme for PQ Improvement at PCC of a Remotely Located Wind–Solar PV-BES Microgrid

The energy poverty in rural areas is due to the intermittent power supply from the existing utility. The proposed remotely located wind–solar photovoltaic array and battery energy storage (BES) supported microgrid, intends to overcome the uncertainty of the renewable power generation by compensating power quality (PQ) disturbances at the point of common coupling (PCC). Robust normalized mixed norm (RNMN) adaptive algorithm filters the load current component to remove the harmonics pertaining due to nonlinear load currents and improves the voltage profile at PCC. It allows the connection of sensitive loads without affecting their life and applicability at PCC. RNMN algorithm provides enhanced convergence rate as well as it reduces the steady-state error effectively. BES controlled by a bidirectional dc–dc converter ensures power supply to the critical loads during scarce generation by renewables resources. Proportional resonant controller provides superior performance over conventional proportional integral controller while dealing with the sinusoidal signals. Rejection of dc offset with effective harmonics elimination is provided by the improved second-order generalized integrator phase-locked loop. The speed regulation of the synchronous generator driven by a wind turbine is achieved by a sensorless field-oriented control technique. The maximum power point of each renewable resource is attained by individual implementation of perturb and observe scheme. The power sustainability is provided to the limited reach microgrid while overcoming the issues of load curtailment and PQ. Test results obtained on a developed prototype demonstrate the applicability of the control algorithms promising solution in controlling the intermittency and fluctuations related complex issues faced by the remotely located microgrid.

DESAIN DAN IMPLEMENTASI SECOND ORDER GENERALIZED INTEGRATOR-PHASE LOCKED LOOP (SOGI-PLL) UNTUK TEGANGAN SATU FASA MENGGUNAKAN DSPIC30F4011 DENGAN KONTROL PROPORTIONAL INTEGRAL

Grid Side Converter (GSC) is a power converter device that have important role in electrical energy conversion systems especially in the utilization of renewable energy sources in order to be connected to the grid. Based on the grid connection requirements, the GSC should be able to operate even if the grid is experiencing interference. Based on the problem, the GSC control system technically should have ability to detect grid disturbances quickly by using Phase Locked Loop (PLL) method that can provide grid voltage information. Compared with other PLL algorithms, the Second Order Generalized Integrator-Phase Locked Loop (SOGI-PLL) has adaptive-filtering characteristics in adjusting phase information. The SOGI-PLL method in this final project will be implemented for single phase system using dsPIC30F4011 microcontroller with PI controller. PI controller is expected to make the system has a fast response to the changes that occur, because the purpose of the PLL’s own needs is to get the results of grid voltage information such as magnitude, frequency, and phase in realtime. As the results, the SOGI-PLL algorithm through the use of ZMPT101B sensor shows the magnitude, frequency, and phase information is suitable with the grid voltage. The result of phase estimation have also been implemented in the inverter product development project, so that the output voltage inverter is in phase with the grid voltage.

Design of output LCL filter and control of single-phase inverter for grid-connected system

In this paper, an implementation of the control and the synchronization algorithms for a voltage source inverter (VSI) used in a grid-connected structure is carried out. The main purpose is to show the combined operation of the control and synchronization algorithm for achieving the proper behavior of the grid inverter for the single-phase utility grid system. In order to obtain a proper functionality of the system during perturbation, a proportional integral controller structure along with second-order generalized integrator phase-locked loop is designed and used as synchronization algorithm. Another aim is to control power factor at grid, to feed power into the grid and to decrease phase current distortion of VSI. Secondly, the design of the output LCL filter is proposed in this paper. The results of simulations of the inverter system connected to grid (220 V, 50 Hz) using MATLAB/Simulink are also shown. Simulation results confirm that the grid input power factor is nearly one and the distortion of phase current of the proposed system is reduced, causing the total harmonic distortion for various power conditions falls within 5%. The last chapter shows the experimental verifications of the proposed control algorithm.

Mono-component AM–FM Signal Decomposition Based on Discrete Second-Order Generalized Integrator Phase-Locked Loop

A mono-component AM---FM signal decomposition method is proposed using discrete second-order generalized integrator and phase-locking scheme. A discrete second-order generalized integrator (SOGI) is employed in the algorithm as a quadrature signal generator for a center carrier frequency. The outputs from SOGI are in-phase and quadrature components of the AM---FM signal. These components are processed in the discrete phase-locked loop to estimate instantaneous frequency variation and instantaneous amplitude variation. The estimated instantaneous frequency variation is fed back to SOGI to adjust the center frequency. Proposed mono-component AM---FM demodulator is implemented in FPGA platform. The algorithm offers good acquisition time, accuracy, and operating range. Experimental investigations performed on the algorithm prove the efficacy and suitability of the algorithm for mono-component AM---FM demodulation.

A Frequency-Tracking Method Based on a SOGI-PLL for Wireless Power Transfer Systems to Assure Operation in the Resonant State

Wireless power transfer (WPT) technology is now recognized as an efficient means of transferring power without physical contact. However, frequency detuning will greatly reduce the transmission power and efficiency of a WPT system. To overcome the difficulties associated with the traditional frequency-tracking methods, this paper proposes a Direct Phase Control (DPC) approach, based on the Second-Order Generalized Integrator Phase-Locked Loop (SOGI-PLL), to provide accurate frequency-tracking for WPT systems. The DPC determines the phase difference between the output voltage and current of the inverter in WPT systems, and the SOGI-PLL provides the phase of the resonant current for dynamically adjusting the output voltage frequency of the inverter. Further, the stability of this control method is analyzed using the linear system theory. The performance of the proposed frequency-tracking method is investigated under various operating conditions. Simulation and experimental results convincingly demonstrate that the proposed technique will track the quasi-resonant frequency automatically, and that the ZVS operation can be achieved.