Improved Droop Controller for Distributed Generation Inverters in Islanded AC Microgrids

Stability in island microgrids is crucial for efficient power distribution among distributed generation (DG) inverters. Conventional droop control, while effective in power sharing, poses challenges with voltage stability due to frequency and voltage deviations resulting from changing load power. Such deviations can lead to system instability, impacting power flows within each inverter. Therefore, this paper introduces a proposed droop control approach that effectively tackles the issues of frequency and voltage deviation, aiming to restore them to their rated values and significantly enhance transient response in power flows among inverters. The novel method incorporates integrating controllers for frequency and voltage, coupled with the utilization of virtual impedances. These virtual impedances, comprising virtual positive/negative-sequence impedance (VPI/VNI) loops at the fundamental frequency and a virtual harmonic impedance (VHI) loop at harmonic frequencies, play a crucial role in overcoming mismatched line impedance conditions, ultimately improving overall system performance. Simulation results demonstrate the effectiveness and outstanding performance of inverters operating in parallel within an island AC microgrid. The proposed approach ensures stable voltage and frequency levels in all operational states, regardless of varying load conditions

Standalone photovoltaic array fed induction motor driven water pumping system

Due to the absence of energy transmission lines connected to the water pumping sites in remote areas, problems related to the electrical power outages and the environmental degradation caused by fossil fuel. For this one of the most conceived solutions is the photovoltaic water pumping technology which has the advantage of being sustainable and respectful of the environment to supply water to rural areas. To ensure the need of water, especially for domestic use and small communities, in this article, the photovoltaic energy system for autonomous water pumping using the induction motor was presented, particularly adapted to the isolated regions. Pumping system consists of four photovoltaic (PV) panels, boost converter, inverter, induction motor, centrifugal pump and a storage tank. In this study, the output power of a PV solar cell is fully used by proposing the P&O algorithm, where it is used to follow a maximum power point tracking (MPPT) technique. The recommended system is designed, modeled and simulated on the MATLAB/Simulink platform. The efficiency of the proposed algorithm is observed with variable solar sunshine

Active and reactive power sharing in micro grid using droop control

The development of renewable energy contributes to the global objectives of reducing our greenhouse gas emissions, obtaining and increasing our energy efficiency. In the face of these changes, the electric-network must adapt, while maintaining a high level of reliability and a quality of energy production. To meet this objective, it is recommended to use highly developed electrical network by integrating renewable energy sources in order to adapt the energy consumption to their production, using electro-technical software information and telecommunications technologies. We are talking about intelligent grids (Smart Grid). The main objective of the work presented in this paper is the contribution to the study of intelligent network for efficient management of energy produced by several sources linked to the AC bus via the voltage inverters. Numerical simulations have been presented to validate the performance of the proposed active and reactive power controller (Droop Control)

Fuzzy logic control of hybrid systems including renewable energy in microgrids

With a growing demand for more energy from subscribers, a traditional electric grid is unable to meet new challenges, in the remote areas remains the extension of the conventional electric network very hard to do make prohibitively expensive. Therefore, a new advanced generation of traditional electrical is inevitable and indispensable to move toward an efficient, economical, green, clean and self-correcting power system. The most well-known term used to define this next generation power system is Micro Grid (MG) based on renewable energy sources (RES). Since, the energy produced by RES are not constant at all times, a wide range of energy control techniques must be involved to provide a reliable power to consumers. To solve this problem in this paper we present a Fuzzy Logic Control of isolated Hybrid Systems (HRES) Including Renewable Energy in Micro-Grids to maintain a stability in voltage and frequency output especially in the standalone application. The considered HRES combine a wind turbine (WT) and photovoltaic (PV) panels as primary energy sources and an energy storage system (ESS) based on battery as a backup solution. Simulation results obtained from MATLAB/Simulink environment demonstrate the effectiveness of the proposed algorithm in decreasing the electricity bill of customer

Power Quality Improvements in Wind Diesel Power Generation System

<p class="Abstract">Generation of electricity using diesel is costly for small remote isolated communities. At remote location electricity generation from renewable energy such as wind can help reduce the overall operating costs by reducing the fuel costs. However, the penetration of wind power into small diesel-based grids is limited because of its effect on power quality and reliability. This paper focuses on the combination of Wind Turbine and Diesel Generator systems for sustained power generation, to improve the power quality of wind generation system. The performances of the optimal control structure are assessed and discussed by means of a set of simulations.</p