Performance and power quality assessment of a linear electric generator focused on microgeneration applications

Abstract

The use of new generation devices based on renewable energy is a subject that increasingly becoming more important for the development of new distributed generation systems; one device developed for this purpose is the permanent magnet linear generator (PMLG). This work deals with the performance and power quality assessment of the PMLG under 2 different generation scenarios of microgeneration: the wave energy converter and the free piston engine linear generator. The performance of the PMLG is evaluated using the finite element method and experimental results under steady state condition of a 100-W prototype are presented to test and validate the proposed process design. The actuator displacement inside the PMLG was obtained from the equation that governs the movement of the 2 systems under study; this displacement was the excitation function used to conduct the simulation and the laboratory experiments. This work contributes to the design and development of power components devoted to microgeneration and creates the need for the modelling and development of power electronic converters for helping in control and power quality. KEYWORDS distributed generation, linear generator, microgeneration, piston generator, power quality, wave energy converter 1 | INTRODUCTION Currently, with the microgeneration arises, new alternatives on energy conversion devices are able to take alternative and sustainable energy, as in the case of permanent magnet linear generator (PMLG). This generator has been developed and tested to harness wave energy, 1-4 and more recently, in free piston energy converters 5-7 with applications in hybrid vehicles. 8,9 For the design of the PMLG, some previous contributions were reviewed, 1 study 10 describes and develop this device to be coupled to a wave energy converter (WEC) system using a buoy and another study 11 uses a submerged air-filled chamber known as Archimedes wave swing. In the energy conversion system, there are nonuniform and irregular movements of the waves in WEC, which affects the voltage and output power of the PMLG. With this in mind, De la Abbreviations: FEM, Finite element method; WEC, wave energy converter; PMLG, permanent magnet linear generator; FPEG, free piston electric generator; THD, total harmonic distortion; 2S, 2-stroke mode; 4S, 4-stroke mode; A s , stator surface dimension (m 2 ); D s , stator diameter (m); L s , stator axial length (m); B m , average magnetic flux density in stator (T); J m , current density in stator conductors (A/m 2 ); v m , linear velocity of magnets on the shaft (m/s); A a , shaft cross section (m 2 ); D a , shaft diameter (m); A g , cross section of the air gap tub (m 2 ); D g , mean diameter of air gap (m).; B a , average magnetic flux density in actuator (T); B g , average magnetic flux density in air gap (T); N s , number of conductors in stator windings.; V gen , induced voltage (U); P losses , electrical losses in PMGL (W); P in , desired power rate (W); P out , output power rate (W); P mec , mechanical losses due friction (W); %η, effi...

A Robust Generator–Harvester for Independent Sensor Systems

“…In this context, a broad range of approaches are examined to yield instantaneously delivered/transmitted electrical power in the range of P = 10-10,000 W. The published articles and papers can be classified into several groups. The first one embraces the area of designing and solving the electrical, electronic, and electromagnetic parts of the projected devices; prominent sources include, above all, [5][6][7][8]. Another group addresses the harvester/generator drive issues, often in relation to combustion engine functions and parts [9][10][11][12].…”

“…Other published articles or papers discuss, for instance, an approach that relies on deploying a linear generator to convert the mechanical vibrations of a car into electrical energy [44]. Some of the researchers also analyze the performance and quality of a linear microgenerator, including testing to exploit the energy from the mechanical propagation of waves with free pistons [7].…”

“…The simulation and experimental verification of the parameters of the equivalent circuits and the rotor/stator core losses via the FEM are addressed in article [37]. An evaluation of the related impact of the electrical parameters, load, and drive dynamics is proposed in [7,8].…”

“…Between the years 2000 and 2020, the trends of energy saving, energy system independence, energy processing efficiency, and energy harvesting based on electromagnetic field principles [1] reached almost all industries. The field of energy harvesting, or the concept of energy transduction [2][3][4], does not cover the entire area of energy production and processing to convert diverse forms of energy into electricity; this domain includes only a limited part of the principles [5][6][7][8] and corresponding device designs [9][10][11][12] that allow exploiting unused types of energy for a given purpose [13,14]. In power generation, specific energy conversion principles still remain to be included, such as the conversion of energy from flowing media (water, air) and the conversion of incident RF electromagnetic waves, namely, photovoltaic systems, into electricity [15][16][17].…”

Model predictive control of direct‐drive wave power generation system connected to DC microgrid through DC cable

“…The results of this approach were compared with genetic algorithm‐based PI under different fault conditions. The performance and power quality assessment of the LPMSG in wave energy converter was studied in Reference 14.…”