An analytical technique using the `Newton-Raphson' method is presented to identify the saturated magnetising reactance and the generated frequency of a self-excited induction generator for a given capacitance, speed and load. The technique is shown to be very efficient in analysing such systems under steady state. Computed results are compared with the experimentally obtained values on a laboratory machine, and a reasonable correlation has been observed. Effects of various system parameters on the steady-state performance have been studied, and the results presented provide guidelines for optimum design of such systems.

Analysis of self-excited induction generators

https://cyberleninka.org/article/n/696659.pdf

Comparative assessment of maximum power point tracking procedures for photovoltaic systems

Rapid industrialization and its automation on the globe demands increased generation of electrical energy with more reliability and quality. Renewable energy (RE) sources are considered as a green form of energy and extensively used as an alternative source of energy for conventional energy sources to meet the increased demand for electrical power. However, these sources, when integrated to the utility grid, pose challenges in maintaining the power quality (PQ) and stability of the power system network. This is due to the unpredictable and variable nature of generation by these sources. The distributed flexible AC transmission system (DFACTS) devices such as distributed static compensator (DSTATCOM) and dynamic voltage restorer (DVR) play an active role in mitigating PQ issues associated with RE penetration. The performance of DFACTS devices is mostly dependent on the type of control algorithms employed for switching of these devices. This paper presents a comprehensive review of various conventional and adaptive algorithms used to control DFACTS devices for improvement of power quality in utility grids with RE penetration. This review intends to provide a summary of the design, experimental hardware, performance and feasibility aspects of these algorithms reported in the literature. More than 170 research publications are critically reviewed, classified, and listed for quick reference for the advantage of engineers and academician working in this area.

/pdf/comprehensive-review-of-distributed-facts-control-algorithms-3abt9977a4.pdf

Comprehensive Review of Distributed FACTS Control Algorithms for Power Quality Enhancement in Utility Grid With Renewable Energy Penetration

Review of savonius wind turbine design and performance

This study presents analysis, design and implementation of a microcontroller based electronic load controller (ELC) for efficient voltage regulation of a three-phase self-excited induction generator (SEIG) feeding single-phase loads in remote locations. The proposed ELC has an uncontrolled rectifier, a filtering capacitor, an insulated gate bipolar transistor switch and a series dump load. The pulse-width modulation (PWM) pulses with appropriate duty cycle are generated using the dsPIC30F6010 microcontroller. The duty ratio is determined based on the closed-loop control scheme which decides the amount of power diverted to the dump load. The proposed SEIG–ELC system demonstrates an effective power switching between the main load and the dump load thereby providing an efficient voltage regulation at the machine terminals. The controller is modelled in Matlab/Simulink and the simulated results are validated by experimental results.

https://ietresearch.onlinelibrary.wiley.com/doi/pdf/10.1049/iet-rpg.2012.0204

Efficient voltage regulation scheme for three-phase self-excited induction generator feeding single-phase load in remote locations

This paper explores methodologies to use a three-phase self excited induction generator (SEIG) for providing single phase power using appropriate renewable energy sources with suitable prime movers. It presents the general operating principle and steady-state analysis of a three-phase self excited induction generator (SEIG) having star/delta connected stator winding feeding three-phase balanced/unbalanced and single-phase loads. An approach based on symmetrical component theory is employed to derive the performance equations. Analyses are carried out on different capacitor topologies to establish their suitability for single-phase operation of the three-phase SEIG. The “fsolve” optimization tool of Matlab is used to obtain the excitation frequency and saturated magnetizing reactance. The theoretical analyses and simulations are validated by experimentation on a 7.5 kW, 415 V, 14.5 A, 50 Hz, four-pole, three-phase induction machine working as SEIG. The analyses brings out the comparison between different terminal capacitor connections and highlights the merits of one scheme over the other for making right choice while feeding single-phase loads. The strategies to be adopted for different sources in using SEIG for 1- phase loads are explained.

Self excited induction generator for renewable energy applications to supply single-phase loads in remote locations

The generation of electric power using self excited induction generation (SEIG) is a viable option in remote and rural areas where grid electricity is not available. The generated voltage and frequency of these machines, however, varies with varying loads. This characteristic can be resolved either by adjusting the values of the excitation capacitance or by controlling the prime mover speed. Further, in a single-point constant power application, where the machines deliver a fixed amount of power, the electronic load controller (ELC) can be used to switch-in or switch-out a dump load whenever the consumer load decreases or increases respectively. This paper presents a detailed analysis and the design of a microcontroller based SEIG -ELC system intended for stand-alone pico hydro power generation. The simulated performance of the controller is supplemented by experimental results.

/pdf/design-of-a-microcontroller-based-electronic-load-controller-51u8peve8s.pdf

Design of a Microcontroller Based Electronic Load Controller for a Self Excited Induction Generator Supplying Single-Phase Loads

An hybrid renewable energy sources consisting of solar photovoltaic, wind energy system, and a microhydro system is proposed in this paper. This system is suitable for supplying electricity to isolated locations or remote villages far from the grid supply. The solar photovoltaic system is modeled with two power converters, the first one being a DC-DC converter along with an maximum power point tracking to achieve a regulated DC output voltage and the second one being a DC-AC converter to obtain AC output. The wind energy system is modeled with a wind-turbine prime mover with varying wind speed and fixed pitch angle to drive an self excited induction generator (SEIG). Owing to inherent drooping characteristics of the SEIG, a closed loop turbine input system is incorporated. The microhydro system is modeled with a constant input power to drive an SEIG. The three different sources are integrated through an AC bus and the proposed hybrid system is supplied to R, R-L, and induction motor loads. A stati...

https://www.tandfonline.com/doi/pdf/10.1080/23311916.2015.1005000

Power quality analysis of hybrid renewable energy system

This paper presents modeling and power quality analysis of an integrated renewable energy system (RES) aimed at supplying electrical power to communities residing at remote locations, far from the grid supply. A decentralized power generation in the form of integrated system is proposed comprising of a solar photovoltaic (PV) system, a wind energy system (WES) and a micro hydro system (MHS) to supply required electric loads. The PV system is modeled with a dc-dc converter for regulating dc output voltage; a maximum power point tracking system (MPPT) is incorporated in order to achieve a reliable power output. The WES is modeled with a variable speed wind-turbine set with fixed pitch angle and the set drives a capacitor excited asynchronous generator (CAG). The CAG, in turn, is modeled with a closed loop turbine input system to account for the drooping characteristics of the asynchronous generator. The MHS consists of a constant power CAG. The three different sources are integrated and connected to a common ac bus and the performances of the system under varying loads are presented. A static synchronous compensator (STATCOM) is proposed in this work for reactive power compensation which, in turn, is expected to improve the power quality of the integrated system. The STATCOM is realized by means of a three-phase IGBT based current controlled voltage source inverter (CC-VSI) with a self-supporting dc bus. The complete system is modeled and simulated using Matlab/Simulink. The results obtained are presented and they are found to be satisfactory.

Sarsing Gao

Papers

Efficient voltage regulation scheme for three-phase self-excited induction generator feeding single-phase load in remote locations

Self excited induction generator for renewable energy applications to supply single-phase loads in remote locations

Design of a Microcontroller Based Electronic Load Controller for a Self Excited Induction Generator Supplying Single-Phase Loads

Power quality analysis of hybrid renewable energy system

Modeling and power quality analysis of integrated renewable energy system