Improved generalised integrator for optimal dispatch of SyRG‐based pico‐hydro‐PV system

Abstract

The fluctuating outputs from renewable energy sources (RESs) and variable load power demand deteriorate the current quality, thus an improved generalised integrator with a frequency-locked loop (IGI-FLL) control strategy is used, which is not only easy but simple to attain a quick and precise fundamental extraction. IGI-FLL control method is utilised with all-pass filter and is capable to accomplish enhanced harmonics, noise and DC offset rejection ability while estimating fundamental component of the load current. In addition, the FLL structure is used to increase the frequency immunity against voltage variations. It provides improved steady-state and dynamic performances with flexibility in parameter tuning in comparison to SOGI-FLL algorithm. It also presents a cost-effective and robust genetic algorithm (GA)-based optimisation to provide optimum battery charging and discharging power while satisfying the state-of-charge (SOC) limits under RES uncertainty. In this islanded microgrid, a Synchronous Reluctance Generator for pico-hydro and photovoltaic array is used so that this hybrid system utilises maximum solar PV array power, matches the load, or else charges the battery energy storage while maintaining power balance in the microgrid. Comparative outcomes authenticate the efficacy of the algorithm to handle the issue of RES uncertainty and load unbalance in an islanded microgrid.

Implementation of variable gain controller based improved phase locked loop approach to enhance power quality in autonomous microgrid

“…Thus, the charging/discharging power of the ESS is computed while keeping the MG and SOC restrictions in consideration. Furthermore, the power equation of the MG under load change is shown below to maintain the needed power balance. where and are the ESS power, total loss of power and power of nonlinear load in the MG 28 . The ripple filter reduces the high‐frequency noise produced by the VSC switching.…”

“…where p ess ,p loss and p load AC are the ESS power, total loss of power and power of nonlinear load in the MG. 28 The ripple filter reduces the high-frequency noise produced by the VSC switching. The ripple filter is a low pass filter that is made up of a series of capacitors and resistances with values of 10 μF and 5 Ω respectively.…”

“…A VCO less PLL based VSC is described to evaluate fundamental component and phase angle under varying load conditions and this control reduces the computational burden and the steady state error 26 . A ROGI‐FLL and lattice wave digital filter based approach is implemented to compute the frequency and phase component 27,28 . An AANF based control is being used to regulate the RES's power, 22 the control provides dc offset rejection with reduced steady state error and frequency estimation 29 .…”

“…26 A ROGI-FLL and lattice wave digital filter based approach is implemented to compute the frequency and phase component. 27,28 An AANF based control is being used to regulate the RES's power, 22 the control provides dc offset rejection with reduced steady state error and frequency estimation. 29 The VLGLMS based control is also utilized to extract the sinusoidal reference current.…”