Axial Flux Permanent Magnet Generator Research Articles

Design and Construction of a 3-Phase Axial Type BLDC Generator for PLTB

The need for electrical energy in remote areas to improve community welfare must be a concern for universities. The government's ability to build new electricity sources is very minimal because it requires large infrastructure and costs, but the government continues to strive to develop new power plants. Therefore, it is necessary to strive for innovation to build power plants from renewable energy sources. There is a need to use renewable energy as an alternative to replace electrical energy which is increasingly in crisis. One alternative energy that is easy to make is energy that uses magnetic force as a model for generating electricity. Brushless Direct Current (BLDC) motors are an alternative to current DC motors. This three-phase permanent magnet axial flux generator is specially designed for vertical-type wind turbines. This generator consists of two stators and one rotor. where each stator consists of 9 coils and the magnet used is a neodymium permanent magnet. Based on test results, this generator can produce a voltage of 12.57 VDC with a wind speed of 6.84 m/s. So, it can turn on DC lights and charge DC batteries. This three-phase axial BLDC generator was tested in 3 stages, namely without load, using battery load, and DC-light load with wind conditions depending on natural conditions.

RANCANG BANGUN GENERATOR MAGNET PERMANEN FLUKS AKSIAL PADA PROTOTYPE PEMBANGKIT LISTRIK TENAGA BAYU (PLTB) SUMBU VERTIKAL

Axial flux permanent magnet generators are easy to manufacture because only the rotor and stator are aligned. Axial flux generators are one of the right choices for wind power plants due to the large number of magnetic poles, high electrical power density, and easy-to-increase power capacity. The axial flux type permanent magnet generator is designed with a speed of 600 rpm, a frequency of 50 Hz, a voltage of 12 V, a power of 7 Watts, 1 phase, 10 pairs of Neodymium Iron Boron (NdFeB) type magnetic poles, and 5 copper wire coils measuring 0.6 mm in diameter with a total of 301 turns. This vertical-axis wind farm test uses an axial flux permanent magnet generator with a 5? resistor load and is assisted by a blower. The blower is used to get a constant turbine rotation in accordance with the results of wind speed measurements taken for 3 days on the rooftop of the electrical engineering lecture building, namely the wind speed range of 3-5 m/s. Based on these tests, the generator is able to produce a voltage of 1.5 V, a current of 0.2 A, a power of 0.27 Watt, and a generator efficiency level of 0.63% at a wind speed of 3 m/s. It also produces a voltage of 4.4 V, a current of 0.7 A, a power of 2.77 Watt, and a generator efficiency level of 0.97% at a wind speed of 5 m/s.

Integrated Design and Optimization of a Direct Drive Axial Flux Permanent Magnet Generator for a Tidal Turbine

The C-GEN is a novel topology of direct drive air-core permanent magnet generator being developed at University of Edinburgh [1]. The topology has many benefits such as; absence of cogging torque, reduced mass and ease of manufacturing. A 20 kW prototype test rig and 15kW machine for a wind turbine has been manufactured and tested previously. Initial sizing studies for wind turbines indicate that the C-GEN concept will be up to 50% lighter than conventional iron cored PM direct drive generators [1]. In addition to the applications wind turbines, C-GEN technology can also be implemented for marine energy power take-off systems. To investigate that, a feasibility study is being undertaken in collaboration with two wave and two tidal energy companies. In this paper, design and optimization method of an axial flux permanent magnet generator for a tidal energy converter device has been investigated. An analytical optimization tool is designed that combines electromagnetic, structural and thermal aspects of the machine design. A genetic algorithm optimization method has been utilized based on the operation conditions of generator and pre-defined constraints on dimensions and material limitations. The output of the analytical design tool is compared with the electromagnetic FEA simulations. The results showed that proposed analytical calculation method is consistent with FEA results

Functional simulation model of the axial flux permanent magnet generator

Functional simulation model of the axial flux permanent magnet generator

Comparative research on the speed performance of Axial flux Permanent Magnet Generator (PMG)165 with manufacturing specification and experimental for implementation in the Low-Speed Wind Turbine System

This paper is on working on energy assessment of generator’s voltage, current and power output based on the generator speed. Today, demand of power is increasing because of technology advancement and increasing electrical devices being manufactured and installed. For this reason, the generator applied in renewable energy is recommended. It must be improved because it is an important component inside the energy system in producing enough power. This research is used the DC Motor function as prime mover and direct shaft to the shaft connection of AFPM165. The parameters of the investigational research are generator speed (rpm), DC current value form generator output (Amp), and voltage value (V). The speed of DC Motor has been gradually increases, from 0 ∼ 300 rpm by adjusted speed adjustment knob. The series circuit 15-ohm resistor and 5 Watts lamp to make it total 19-ohm constant as a load. The result is presented that the more speed of generator, the more voltage, and current it can be inducted. The findings of the study are presented that there is a difference between the factory specification and the experiment where the experimental value is more than the factory specification value which is 11.43% variation.

Overview of Axial Flux Permanent Magnet Generator for Small-Scale Industry

A magnetic generator is not like a conventional generator that is produced by the coil. Consequently, this generator used the permanent magnetic field to produce magnetic flux energy. Although, most of the permanent magnet designs produce less aggressive copper winding. This paper provides an overview of axial flux permanent magnet generators for small-scale industries. First of all, the classification and a detailed overview of permanent magnet generators are presented first. The main characteristics of the generators together with their benefits and drawbacks are highlighted. Additionally, an overview of the most recent machine developments is also presented. The design of convenient permanent magnet generators that have been used to create small-scale generator varieties is then reviewed to conclude the most suitable design among axial flux which is the sandwiched construction.

Air‐cored axial flux permanent magnet generator for direct driven micro wind turbines

AbstractThis paper presents the development of an Air‐Cored Axial Flux Permanent Magnet Generator (ACAF PMG) integrated for direct battery charging scheme for urban and rural micro‐wind turbine applications rated at 1 kW. The proposed generator has a Single Stator Double Rotor configuration with a relatively short axial length. In this paper, the analytical model for generator sizing is presented and the main parameters are defined. Novel analytical model is presented to determine the required number of turns for each phase in order to produce a balanced voltage in the three phases. The generator is electromagnetically analyzed using Finite Element model and simulated using Matlab/Simulink to predict its performance under several operating conditions. The effect of retainment ring type on the generator performance is also demonstrated. The machine is harnessed to a battery bank via a three‐phase fully controlled converter using six bridge thyristors to regulate the output voltage delivered from the generator to the battery. Generator model and simulation results are validated via experimental tests. The preliminary experimental results showed a good match with the simulation results. Moreover, the proposed machine is compared favourably with other counter machines of similar configuration and power ratings in terms of machine size, power‐to‐weight ratio, and voltage regulation. This paper therefore demonstrates the concrete benefits of utilizing the axial flux PMG in scavenging energy to generate electrical power from micro wind turbines.

Electromagnetic shielding tests of a permanent magnet generator

In the present work, some tests on the electromagnetic interference issues of a new designed and constructed axial flux permanent magnet generator have been presented. The machine itself has multiple special laminated cores (i.e., 12) and 24 windings in the stator component with two active sides. Machine operates in 3 phases and uses disc type permanent magnets on two rotors at two sides in a sandwiched formation. Rotors have 32 magnets and freely rotates at the vicinity of stable stator within a certain air gap. The electromagnetic interference measurements have been realized for different distances and directions from the machine. Besides, the effects of different frequencies are also evaluated following the tests. It has been concluded that the shielding material shape is very important for the optimum shielding results.

A Counter-Rotating Double-Rotor Axial Flux Permanent Magnet Generator for Wind Turbine Applications: Design, Simulation, and Prototyping

A Counter-Rotating Double-Rotor Axial Flux Permanent Magnet Generator for Wind Turbine Applications: Design, Simulation, and Prototyping

Maximum power point tracking control based on inertia force for underwater direct-drive wave energy converter

Underwater direct-drive wave energy converter (UDDWEC) using linear-rotating axial flux permanent magnet generator (LR-AFPMG) can change form of energy conversion and improve conversion efficiency. This paper proposed a maximum power point tracking (MPPT) control based on inertia force in electromagnetic force for UDDWEC which can control the form and magnitude of electromagnetic force including damping force, spring force and inertia force. By adding inertia force in electromagnetic force, the pole location and dynamic response performance can be changed and adjusted. This paper studied the influence of inertial force in electromagnetic force and system response in detail. The research also involved the influence of buoys with different shapes on wave energy capture, the expression of q-axial reference current when inertia force is considered, the necessity of additional damping in the system and power capture width in different sea conditions. According to the hydrodynamic parameters and wave characteristics, the proposed MPPT control was verified through simulation in regular wave and JONSWAP spectrum and the results showed that MPPT control based on inertia force can capture the maximum wave energy and achieve maximum power capture width. Above on this, this control strategy can be a decent candidate for UDDWEC. Finally, a series of flume experiments were carried out to verify the accuracy of hydrodynamic parameters of underwater buoy.

Experimental Investigation of Magnet Grouping Technique in Reduction of Cogging Torque and Total Harmonic Distortions in the Axial Flux PM Generator for Direct Drive Wind Turbine

Generators that have been used in direct-drive wind turbines could be produced with a permanent magnet between the power ranges of 1 kW to 1 MW. The cogging torque is the most significant problem of these generators. In this study, the pole grouping method is suggested to reduce the cogging torque of an axial flux permanent magnet (AFPM) synchronous generator with open slotted. The suggested method includes magnetic analyzes and experimental results of the 14-pole open slotted AFPM generator rotor poles that grouped as 7-7, 4-3-4-3, 3-2-2-3-2-2 and named A, B, C, respectively. Besides obtaining the cogging torque (Tc) data, the most considerable part of the study is to get total harmonic distortion (THDV) and output power (Pout) data in which show the electrical performance of the generator for different grouping angles. The optimum ranges for an AFPM generator were determined as 80% reduction for Tc, 15% reduction for Pout, and below 3% for THDV. The optimum grouping angles for A, B, and C were obtained by experimental studies as 32°, 32°, and 30°, respectively. Experimental results and the magnetic analysis have been shown that optimum values are obtained when the ratio of the pole angle to the grouping angle is

Investigation of different types of winding in counter-rotating double-rotor axial flux permanent magnet machines

ABSTRACT The choice of the winding type has a significant effect on the performance characteristics of the machine, efficiency, weight of the required wire, ease of winding, etc. The purpose of this paper is to investigate the effect of winding type as well as the polarity of magnets on both sides of the stator core on the back electromotive force (Back-EMF) of the counter-rotating double-rotor axial flux permanent magnet generator (CRDR-AFPMG). The winding type influences the produced voltages of the generator. Hence, in this paper, several types of windings, such as the first type of shifted winding, the second type of shifted winding, and the independent winding are investigated to produce three voltages with the same amplitudes and 120 degrees of phase differences. However, it has been found that, among the studied windings, only the second type of shifted winding and independent winding produces three voltages with similar amplitudes and 120 degrees of phase difference. Finally, the suitable type of winding for the proposed machine will be determined, and the performance of the case study machine will be evaluated by finite element (FE) simulation. JMAG designer software is used for this purpose.

Hybrid Weighted Least Square Multi-Verse Optimizer (WLS–MVO) Framework for Real-Time Estimation of Harmonics in Non-Linear Loads

The electric power quality has become a serious concern for electric utilities and end users owing to its undesirable effects on system capabilities and performance. Harmonic levels on power systems have been pronounced to a greater extent with the continuous growth in the application of solid-state and reactive power compensatory devices. Harmonics are the key constituents that are mainly responsible for power quality deterioration. Power system harmonics need to be correctly estimated and filtered to increase power quality. This research work focuses on accurate estimation of power system harmonics with the proposed hybrid weighted least-square multi-verse optimizer (WLS–MVO) based framework. Multi-verse optimizer replicates the phenomenon of the formation of new universes as described by multi-verse theory to solve complex real-world optimization problems. The proposed WLS–MVO framework is tested and validated by estimating the harmonics present in multiple test signals with different noise levels. Amplitudes and phases of harmonics present in the polluted signal were estimated, and the framework computational time was compared with the previously developed technique’s results which are reported in the literature. There was 80% reduction in computational time and 82% improvement in terms of accuracy in estimating harmonics using WLS–MVO as compared to previously developed techniques. The performance of the developed framework is further validated by estimating the harmonics present in the real-time voltage and current waveforms obtained from axial flux permanent magnet generator (AFPMSG), uninterruptible power supply (UPS), and light-emitting diode (LED). The purposed technique technique outperforms the already-developed techniques, in terms of accuracy and computational time.

An effective Hilbert-Huang transform-based approach for dynamic eccentricity fault diagnosis in double-rotor double-sided stator structure axial flux permanent magnet generator under various load and speed conditions

Eccentricity fault in double-sided axial flux permanent magnet generator is very difficult to be detected as the fault generated variations in terminal electrical parameters are very weak and chaotic, especially at the initial stages of the fault occurrence. In addition, one of the most important problems in any fault diagnosis approach is the investigation of load and speed variation on the proposed indices. To overcome the aforementioned difficulty and problems, this paper adopts a novelty detection algorithm based on Hilbert-Huang transform (HHT) which is a time-frequency signal analysis approach based on empirical mode decomposition and the Hilbert transform. It is well suited for reliable fault diagnosis since it is unaffected by transient conditions which make the diagnosis process incur into false alarms. The HHT-based methods has been demonstrated in recent years for rotor and bearing faults detection of induction machine and also for stator faults identification in PM synchronous machines with radial flux structure. This study explores the possibility of applying the technique to the detection of dynamic eccentricity faults in double-rotor double-sided stator structure axial flux permanent magnet generator under variable load and speed conditions. This approach relies on two steps: estimating the intrinsic mode functions (IMFs) by the empirical mode decomposition (EMD) and computing the instantaneous amplitude (IA) and instantaneous frequency (IF) of IMFs using the Hilbert transform. The more significant IMFs are determined by means of Hilbert spectrum, which is applied for accurate eccentricity fault diagnosis. The eccentricity severity can be evaluated based on the IMFs energy value. The theoretical basis of the proposed method is presented. The effectiveness of the proposed method is verified by a series of simulation and experimental tests under different conditions. The results show that the presented approach in this paper is robust against load and speed variations.

Permanent Magnet Selections for AFPM Disc Generators

In this article, the field (FEM) and analytical analyses were used for the optimal selection of magnets material for the Axial Flux Permanent Magnet Generator (AFPMG), without building the prototype before. The tested generator is an axial flux machine which consists of a single stator and two rotor discs with Permanent Magnets (PM). Three-dimensional (3D) ANSYS Maxwell package was used for magnetostatic and transient field (FEM) simulations. Two types of PM were selected for the analysis: Ceramic (also known as “Ferrite”) magnets made from Strontium Ferrite powder and Neodymium Iron Boron magnets (NdFeB). The authors compared obtained electromotive forces (EMF) and generator powers for selected magnets materials, performed FFT analyses of voltages and currents and indicated the optimal solutions. In addition to the operational properties of the AFPMG, the magnet and manufacturing costs were compared.

Designing Air-Cored Axial Flux Permanent Magnet Generator with Double Rotor

The development of renewable energy is carried out to reduce the use of fossil energy, which is decreasing in existence, increasing in price, and having a very long recovery cycle. One of the uses of technology to support renewable energy development is a synchronous machine that can be used to utilize wind and water energy. One type of synchronous machine that is widely used today is the radial flux machine. However, there is a saturation point in their development. Axial flux machines also called disc type machines, are an alternative to radial flux machines due to their compact shape and high-power density. Axial flux machines can be operated as small to medium-scale power plants. Besides that, they are ideal for low-speed applications. An axial flux permanent magnet (AFPM) generator is designed and built in this study. This generator design consists of a dual rotor with twelve permanent magnets and a single stator with nine coils. The primary material used for the stator and rotor is acrylic, while the permanent magnet uses neodymium N52. It is necessary to know the stator and rotor parameters such as distribution factor (kd), pitch factor (kp), and winding factor (kw) for designing the AFMP generator. The AFPM generator is designed to produce a phase voltage of 4.03 V at a nominal speed of 500 r/min. Based on the measurement results, it was found that the phase voltages at a rotating speed of 500 r/min for each phase are VR = 2.94 V, VS = 2.97 V, and VT = 2.95 V. There are differences in the test results and the design. It can be caused by design simplicity that does not consider magnetic saturation and internal reactance, which cannot be ignored but is not included in the calculation.

High-Performance Five-Phase Axial Flux Permanent Magnet Generator for Small-Scale Vertical Axis Wind Turbine

Commonly, electrical energy is generated by using non-renewable energy such as natural gas, coal, and oil. As electrical energy is a basic asset for the development of a region, its utilization is increasing every year, which causes the existence of non-renewable energy to decrease every year. This issue is becoming a serious concern all over the world, which encourages every country to harness energy from renewable energy. Wind energy is a promising candidate for generating electricity today. In wind turbine generation, a three-phase generator is usually used. Along with the rapid development of power electronic devices and efforts to improve generator performances, the use of a multiphase system is considered important for harnessing energy from the wind more efficiently. In this study, a five-phase system is proposed to upgrade the output power and power density of the most qualified AFPMG in the previous study. The Taguchi optimization method is employed to obtain the lowest total harmonic distortion (THD) of the on-load voltage waveform. In addition to the Taguchi method, an Artificial Neural Network (ANN) is also employed to compare the results from the Taguchi method and the results are proven to have an excellent relationship. The data processed for Taguchi and ANN methods are strongly helped by using the finite element method from the Ansys Maxwell software. The performances of the proposed five-phase axial flux permanent magnet generator (FP-AFPMG) show good improvement, especially in THD, ripple torque, and ripple in the rectified voltage.

Design optimization with genetic algorithm of open slotted axial flux permanent magnet generator for wind turbines

ABSTRACT In this study, the design parameters of Open Slotted Axial Flux Permanent Magnet (OSAFPM) Generator for wind turbines are presented using Genetic Algorithms (GA), an optimization algorithm based on natural selection and genetic mechanisms. Electromagnetic analysis of Open Slotted Axial Flux Permanent Magnet generator has been performed by using parameters optimized with Genetic Algorithms. The ANSYS Maxwell program, which uses the finite element method (FEM), has been used for electromagnetic analysis. Compared to ANSYS Maxwell, it is observed that the genetic algorithm significantly reduces the computational time required for design optimization. However, initial design and optimization with Genetic Algorithms have resulted by 8.94% increase in power densities. In addition, 12.71%, 38.62%, 62.02%, and 56.39% improvements have been obtained for air gap magnetic flux density, flux linkage, induced voltage, and current waveforms, respectively. This suggests that optimization with a Genetic algorithm improves the Open Slotted Axial Flux Permanent Magnet generator parameters.

Design and Performance Analysis of Double Axial Flux Permanent Magnet Generator

In this paper, a new permanent magnet generator structure was proposed in order to facilitate the implementation of the permanent magnet generator on small-scale renewable energy-based power generators. Detail characteristics of a double axial flux permanent magnet generator were analyzed. The proposed generator structure consisted of 2-sided rotors equipped with slots for placing permanent magnets. The stator side comprised 3 groups of coreless winding for realizing 3-phase output. Performances of the axial flux double permanent magnet generator were observed involving the output voltage, currents, and power. Two experimental scenarios have been tested to monitor the performance of the generator. In the first scenario, the loading condition which was represented by the star connection of 3 bulbs of 25 W has been considered. The rotational speed of the tested generator in this scenario was 501.9 rotation per minute (rpm). Under those loading circumstances, 3-phase sinusoidal output voltages with frequencies under 50 Hz have been monitored. Above 50 Hz operational frequency, the output voltage waveform slightly changed from sinusoidal to trapezoidal shapes. In the second scenario, the proposed generator was connected to the rectifier to form a DC system. The 45 W load has been considered in this DC scenario. Under the DC system test, 152.2 V output DC voltage, 0.1614 A current, and 24.976 W power have been monitored when the rotational speed of axial flux double permanent magnet generator was 847.9 rpm.

Axial-Flux Permanent-Magnet Generator Design for Hybrid Electric Propulsion Drone Applications

This paper presents the design of an axial-flux permanent-magnet (AFPM) generator used for hybrid electric propulsion drone applications. The design objectives of the AFPM generator are high power density, which is defined as output power per generator weight, and high efficiency. In order to satisfy the requirements for the target application and consider the practical problems in the manufacturing process, the structure of the AFPM generator comprising a double-rotor single-stator (DR-SS) was studied. In order to determine the rotor topology and stator winding specifications that had the greatest impact on performance in the DR-SS type design process, we selected three rotor models according to the arrangement of the magnetization direction and three stator models according to the coreless winding specifications. These models were first compared and analyzed. Then, a 3-D finite element method was performed to calculate the magnetic, mechanical, and thermal characteristics of the designed models. By consideration of the output power, efficiency, temperature, and mechanical stability, etc., a topology suitable for the design of generators for UAV systems was determined and manufactured. The reliability of the design result was confirmed through the test.