This article presents the control of a three-phase three-wire (3P-3W) dual-stage grid-tied PV-battery storage system using a multi-objective grass-hopper optimization (MOGHO) algorithm. The voltage source converter (VSC) control of the presented system is implemented with adaptive kernel width sixth-order maximum correntropy criteria (AKWSOMCC) and maximum power point tracking (MPPT) control is accomplished using the variable step-size incremental conductance (VSS-InC) technique. The proposed VSC control offers lower mean square error and better accuracy, convergence rate and speed as compared to peer adaptive algorithms, i.e., least mean square (LMS), least mean fourth (LMF), maximum correntropy criteria (MCC), etc. The adaptive Gaussian kernel width is a function of the error signal, which changes to accommodate and filter Gaussian and non-Gaussian noise signals in each iteration. The VSS-InC based MPPT is provided with a MOGHO based modulation factor for better and faster tracking of the maximum power point during changing solar irradiation. Similarly, an optimized gain conventional PI controller regulates the DC bus to improve the power quality, and DC link stability during dynamic conditions. The optimized DC-link generates an accurate loss component of current, which further improves the VSC capability of fundamental load current component extraction. The VSC is designed to perform multi-functional operations, i.e., harmonics elimination, reactive power compensation, load balancing and power balancing at point of common coupling during diverse dynamic conditions. The MOSHO based VSS-InC, and DC bus performance is compared to particle swarm optimization (PSO) and genetic algorithm (GA). The proposed system operates satisfactorily as per IEEE519 standards in the MATLAB simulation environment.

The presented work employs the multiple random feature kernel mean p-power algorithm (MRFKMP) for the voltage source converter (VSC) control of a three-phase four-wire grid-tied dual-stage photovoltaic-hybrid energy storage system (HESS) to achieve multiple objectives during various induced dynamic conditions. The proposed control enables the VSC to accomplish manifold goals, i.e., reactive power compensation, power quality enhancement, load, power balancing at common coupling point and grid voltage balancing during unity power factor mode of operation. The proposed system is scrutinized under steady-state and numerous dynamic states such as irradiation variation, specified power mode, abnormal grid voltage, load, and grid voltage unbalancing. The seamless control facilitates the swift resynchronization of the grid as well as maintaining stability during islanding and re-synchronization operations while satisfying the necessary load requirements. The associated HESS consisting of battery and ultra-capacitor is competent enough in managing the interruptions occurring on the grid, load and photovoltaic side. The DC bus voltage is controlled by the PI controller, which is tuned by the generalized normal distribution algorithm and kept at the desired level during diverse operating conditions. The optimized DC bus generates an accurate loss component of current and further enhances the VSC performance. The proposed system is investigated by simulation and found acceptable as per IEEE 519 standards.

In this paper, a Two-Level, Three-Phase, Reduced-Switch (2L3PRS) Voltage Source Converter (VSC) based Distribution Static Synchronous Compensator (DSTATCOM) integrated with a grid-tied solar photo-voltaic (PV) array has been discussed and its performance investigation has been carried out. A versatile control strategy is proposed which gives the system maximum power point tracking capability with stepped perturbation and observation (P&O) algorithm and the grid current is maintained at unity power factor. The layout in addition to the control technique helps in supplying active power to the power grid and feeding active and reactive power demand of the 3-phase reactive unbalanced load. Modified Synchronous Reference Frame (MSRF) theory-based current control methodology is implemented to sustain DC-link voltage and to maintain the voltage balancing across split capacitors under all loading conditions. This modified algorithm generates switching pulses for three-phase VSI with only four IGBT switches for fulfilling the desired objectives like maintaining a constant DC link voltage, balancing split-capacitor voltages, balancing the power-sharing between the power grid and the solar-PV energy system, balancing the grid currents and voltages in case of unbalanced loading conditions and maintaining unity power factor operation of the grid by making the D-STATCOM compensate for load reactive power. The proposed system is replicated in MATLAB/Simulink using SimPowerSystems software-based environment. The experimental outcomes have been obtained with a digital real-time simulator to vindicate the simulation results. The experimental, as well as simulation results of the proposed real-time based model, are demonstrated for three unbalanced single-phase inductive linear loads and with a load on one phase kept open in Power Factor Correction (PFC)mode of operation of D-STATCOM.

This paper presents the stability improvement of the three-phase four-wire (3P-4W) grid-tied PV-hybrid energy storage system (HESS) using chaotic grew wolf optimization (CGWO) for DC bus voltage $\left(V_{dc}\right)$ and AC bus voltage $\left(V_{pcc}\right)$ control. The CGWO tuned fractional order proportional–integral (FOPI) controllers reduce the $V_{dc}$ and $V_{pcc}$ variations during diverse, dynamic conditions, i.e., sudden irradiation variations, deep voltage sag/swell, etc. The DC bus is responsible for the current injection/extraction control, maximum PV power extraction, bi-directional power flow, dc second-harmonics component elimination, and active power balance. At the point of common coupling (PCC), the AC bus is accountable for bi-directional power flow and active and reactive power control. The two-level voltage source converter (VSC) is controlled by a novel variable step-size incremental least mean square (VSS-ILMS) in zero voltage regulation (ZVR) mode. Due to its varying step size, VSC control is less prone to noise signals offers better stability, improved convergence rate, dc offset rejection, and tracking speed during dynamics, i.e., large oscillations. A battery and ultracapacitor are coupled to the DC link by buck-boost converters in the HESS. To regulate power transit between the DC bus and the grid, the HESS current control technique is designed to shift frequently from charging to discharging stage and vice versa. The novelty of the PV-HESS system lies in CGWO tuned VSS-ILMS control of VSC, which effectively and efficiently filter out the active fundamental constituents of load current and eliminate dc offset from VSC output. The HESS control maintains the DC bus voltage profile by absorbing and delivering energy (during dynamic conditions) rather than curtailing it. The presented system is simulated in a MATLAB/SIMULINK environment. The simulation results in graphical and numerical forms verify the stable and satisfactory operation of the proposed system as per IEEE519 standard.

The world today is plagued with problems of increased transmission and distribution (T&D) losses leading to poor reliability due to power outages and an increase in the expenditure on electrical infrastructure. To address these concerns, technology has evolved to enable the integration of renewable energy sources (RESs) like solar, wind, diesel and biomass energy into small scale self-governing power system zones which are known as micro-grids (MGs). A de-centralised approach for modern power grid systems has led to an increased focus on distributed energy resources and demand response. MGs act as complete power system units albeit on a small scale. However, this does not prevent them from large operational sophistication allowing their independent functioning in both grid-connected and stand-alone modes. MGs provide greater reliability as compared to the entire system owing to the large amount of information secured from the bulk system. They comprise numerous sources like solar, wind, diesel along with storage devices and converters. Several modeling schemes have been devised to reduce the handling burden of large scale systems. This paper gives a detailed review of MGs and their architecture, state space representation of wind energy conversion systems & solar photovoltaic (PV) systems, operating modes and power management in a MG and its impact on a distribution network.

The presented system is a three-phase three-wire (3P–3W), seamless, capable, dual-stage PV power generation system without battery storage for rural residential loads to ensure a continuous power supply during the daytime. This system effortlessly shifts from the grid-connected (GC) mode to the standalone (SA) mode when the grid utility is unavailable. During the GC mode, a voltage source converter (VSC) is regulated by the polynomial zero-attracting least mean square (PZA-LMS) algorithm-based current control scheme. During the GC mode, the power balance is achieved at the point of common coupling (PCC) by exchanging active power with the grid, whereas the VSC delivers reactive power. Considering the low efficiency of PV power generation systems, an incremental conductance (InC)-based maximum power point tracking (MPPT) algorithm is necessary for the maximum power extraction out of a PV array. During the unavailability of the grid, the presented system operates in the SA mode, when the load is delivered with PV power only via VSC. Considering the high cost of the battery storage system (BSS), bi-directional converter, and charge control circuitry incurred by rural consumers, they were omitted from the system. Without a BSS, the InC-based MPPT is executed in the derated mode, extracting the PV power to exactly match the load demand. Without derated PV power generation operation, the load may be damaged due to excess PV power flow to the load end or the load may remain underpowered, leading to load shedding or complete disconnection. A synchronous reference frame (SRF)-based voltage control scheme is responsible for the VSC control during the SA operation of the system. The presented system performance was observed and found satisfactory during the irradiation variation, load balancing, islanding, and re-synchronization of the grid. The presented system was found to carry out harmonics suppression and active and reactive power balance at the PCC during both the GC and SA modes. The grid’s total harmonics distortion (THD) levels were shown to be kept below 5% as per the IEEE 519 standard in the GC mode.