BLDC Machine Research Articles

Assessment of photovoltaic powered flywheel energy storage system for power generation and conditioning

Energy storage and power conditioning are the two major issues related to renewable energy-based power generation and utilisation. This work discusses an energy storage option for a short-term power requirement, which also acts as a power conditioner. The flywheel, an old invention, is included in the electrical power generation arrangement to achieve energy storage and power conditioning requirements. A Photovoltaic solar system is used as a primary source from which the required DC voltage is obtained through an SPWM-based DC-DC converter. This power is fed to an arrangement consisting of a BLDC machine as prime mover, which drives a mass of flywheel. An alternator connected with the motor and flywheel to supply a 1000 W load. The flywheel is designed to take care of the dynamic stability assisted by a suitably designed controller unit and supporting power supply units t ensure the system's reliability. Hence a conditioned and reliable power supply is provided to the load. This research aims to decide on the dimensions and material of the flywheel to be used, which was achieved using ANSYS. Two different materials were selected, and stress analysis was done to ensure their suitability as an energy storage medium in the power generation system. Similarly, the converters and controllers were simulated using MATLAB to fit them to the renewable power generation scheme based on which a working model is fabricated, and tested through proper commissioning, to get the aimed objectives. The outcome of simulation and experimentation were compared, and suitable illustrations were given to prove the successful implementation of a flywheel-based energy storage system.

Исследование характеристик бесконтактной машины постоянного тока при косвенном измерении момента нагрузки

Vector control of an induction motor with indirect torque measurement eliminates the need for a torque sensor. This approach is applicable to study the characteristics of BLDC machine loaded by an induction machine powered by a frequency converter. A mathematical model of a BL DC machine loaded by an induction electric drive and the implementation of this model in the SimInTech dynamic simulation environment are considered. As a result of mathematical modeling, transient processes in terms of speed and Speed-Torque curve are obtained. Comparison of the values of characteristic points with specification data confirms the correctness of the mathematical model and the possibility of using indirect measurement of the torque set by the frequency converter to study the characteristics of a BL DC machine.

Modelling, performance assessment and transient analysis of brushless DC motor by controller techniques

This paper investigates steady state and transients' performance of Brushless Direct Current Motor (BLDC) motor and collates the performance of Proportional Integral (PI) and Proportional Integral Derivative (PID) Controller. Speed and torque behavior is most valuable nowadays for home appliance and other applications. The torque in motor is produced with effect of magnetic field and current. Magnetic field is generated in motor by the strong permanent magnet, and motor current depends upon voltage control and Eb, which is done by field and speed motor. In order to obtain required torque and speed at a particular load, current required must be controlled. The transient or dynamic response analysis is done with transfer function of BLDC motor obtained by the Laplace transform of equivalent circuit equation. The trapezoidal type BLDC machine is controlled using 3-phase Inverter Bridge. The commutation sequence is done with hall sensor and gate pulses. The simulation work is done in MATLAB/ Simulink software and mathematical model is evaluated. The analysis is done to know the performance of how quickly the transient reduces and gives smooth operation for various applications.

Automatic Tolerance Analysis of Permanent Magnet Machines with Encapsuled FEM Models Using Digital-Twin-Distiller

Tolerance analysis is crucial in every manufacturing process, such as electrical machine design, because tight tolerances lead to high manufacturing costs. A FEM-based solution of the tolerance analysis of an electrical machine can easily lead to a computationally expensive problem. Many papers have proposed the design of experiments, surrogate-model-based methodologies, to reduce the computational demand of this problem. However, these papers did not focus on the information loss and the limitations of the applied methodologies. Regardless, the absolute value of the calculated tolerance and the numerical error of the applied numerical methods can be in the same order of magnitude. In this paper, the tolerance and the sensitivity of BLDC machines’ cogging torque are analysed using different methodologies. The results show that the manufacturing tolerances can have a significant effect on the calculated parameters, and that the mean value of the calculated cogging torque increases. The design of the experiment-based methodologies significantly reduced the calculation time, and shows that the encapsulated FEM model can be invoked from an external system-level optimization to examine the design from different aspects.

Novel Optimized Shape and Topology for Slotless Windings in BLDC Machines

Slotless windings are commonly used in small size high-speed electrical brushless dc machines. Unlike slotted windings, forced to follow the direction of slots, slotless windings can be freely arranged in the airgap. This represents several opportunities for optimization. Nevertheless, very little research is performed in this domain. This article intends to challenge the traditional way of manufacturing windings. Indeed, most of the windings are made with isolated wire of constant section. However, it is demonstrated here that the performances of a motor can be significantly increased by optimizing the shape of the winding and by selecting nonconstant wire sections. A prototype of the new topology has been manufactured and measurements have demonstrated an increase of the motor constant from 18% to 24% compared to a traditional slotless winding.

Torque optimisation of seven‐phase BLDC machines in normal and degraded modes with constraints on current and voltage

This study proposes several easy-to-implement control strategies when seven-phase axial flux brushless DC machines with trapezoidal back electromotive forces operate in normal and faulty modes by taking into account constraints on voltage and current. The constraints are related to the converter and machine design in terms of maximum values of current and voltage. The considered faults are cases in which one or two phases of the machine are open-circuited. Numerical computations based on analytical formulations are applied to obtain torque-speed characteristics, including the flux-weakening operation. The methods determine current references to ensure the torque optimisations while currents and voltages are within their limits. The usefulness of the methods is verified by numerical results.

RETRACTED ARTICLE: Internet of Things Based Industrial Automation Using Brushless DC Motor Application with Resilient Directed Neural Network Control FED Virtual Z-Source Multilevel Inverter Topology

Internet of Things (IoT) is a high-speed communication technology which has carnal substances or devices entrenched with sensors, system connectivity, which allows to receive and interchange data. Industrial Monitoring and Control is required to assemble all the material information, statistics, and data related to the various industrial processes, motors, machines and devices employed in industrial premises. The technological improvements, remote control and monitoring via communication techniques such as wireless sensor network techniques have been widely used in Industries. Competitive advantages over AC motors make for DC motors to replace other electrical engines in applications stretching from high-speed automation to electric motorbikes. BLDC drives are very popular in many industries, at present automation are added standard, Virtual Z-source multilevel is a respectable optimal that can boost the output voltage of the drive. A novel soft computing based Resilient Directed Neural network (RDNN) found Virtual Z-source multilevel inverter, for BLDC motor drive control to make the system balanced when the load is unbalanced and to reduce the electrical torque pulsation. In this work, the utilization of the RDNN to tackle the reduced harmonics issue in VZS-MLI converters is proposed. This strategy permits active voltage control of the crucial and besides concealment of a particular set of harmonics. The performance is evaluated in various emphasis levels of the different control models. The sensors monitor the technical motor parameters like greatest rise and fall time, topmost overextend and inaccuracy value of load current and voltage in BLDC machine. Then the measured values are sent to the processing unit, which will analyze and display the parameters, where the processing unit also communicates with Gateway module to send information to cloud database for remote monitoring. The system also presents the Automatic and manual control methods to stop or start the BLDC machine to avoid system failures.

A Couple of Generator and Motor as Electric Transmission System of a Driving Shaft to Long Distance Driven Shaft

Wind energy converter commonly converts wind power to shaft and electric power. One of the problems of transmitting shaft power is the limited distance between the driving to the driven shaft. This paper describes an experimental study of electrical transmission from driving to the driven shaft that was carried out on three modes of cable lines transmission. The driving shaft was attached to an electric generator that converts shaft r to electric power. The driven shaft was coupled by electric motor which reconverts the electric to shaft power. The generator and motor were BLDC and BDC permanent magnet electric machines. The distance of the driving to the driven shaft was 300 meters. The electric power was transmitted using wires. The wires consisted of 2 and 3 cables commonly used by peoples and sold in market place. The results showed that electric transmission mode on the experiment has important role on performance of shaft power to electric power conversion on driving generator and energy losses on cables transmission. DC on small wires electric transmission gave total efficiency of 16.2 %. DC on large wires electric transmission gave total efficiency of 32.9 %. AC on large wires electric transmission gave total efficiency of 36.4 %.

Lumped Parameter Thermal Model for Axial flux Surface Mounted Permanent Magnet BLDC Machine

Axial flux surface mounted permanent magnet BLDC machines are of particular interest for power generation in typical and confined conditions. Due to their compactness & high power density, the ventilation and cooling inside axial flux permanent magnet BLDC machine have become increasingly important for further performance improvement. This paper describes a lumped parameter thermal model of Axial flux Surface Mounted Permanent Magnet BLDC Machine. The transient thermal characteristics and steady state temperature of the motor are estimated from a lumped parameter thermal model. The transient characteristic has been also simulated mathematically, developments of a lumped parameter, thermal modelling technique for axial flux permanent magnet generators. Lumped parameter thermal network is developed to predict the motor heat flow and nodal temperatures. The network is composed of 29 interconnected nodes, 63 thermal resistances and 29 capacitors representing the heat process within motor for steady state and transient analysis.

Improving the Dynamic Stiffness in a Self-Sensing BLDC Machine Drive Using Estimated Load Torque Feedforward

This paper presents a load torque estimation method for self-sensing brushless dc drives. Torque ripples in brushless dc machines can be reduced using load torque information. This method uses the terminal voltage, the virtual neutral point voltage, and the dc bus current of the machine. The algorithm uses the variation of successive back electromotive force (back EMF) samples to estimate the rotor speed. The rotor position is estimated by defining an intermediate function of estimated speed and back EMF samples. An estimate of acceleration is used to estimate load torque. The load torque information is used for increasing the dynamic stiffness of the drive. The mathematical background is given and discussed, and the simulations and the experimental results prove the performance of the proposed method.

A Comparative Analysis of Cogging Torque Reduction in BLDC Motor Using Bifurcation and Slot Opening Variation

The utility of PM-BLDC machines is extending its tentacles in industrial arena. The key features of BLDC machines include high starting torque density and extending speed range, though the cogging torque is a threat for its performance. Various techniques have been devised to minimize cogging torque, out of which two approaches Bifurcation and Slot Opening methods have been focused in this paper. Usage of SPEED Software in comparing the reduction of cogging torque for the above two techniques is the highlight of this paper.

Theoretical and Experimental Investigation of Flex-PCB Air-Gap Windings in Slotless BLDC Machines

Slotless brushless dc motors find more and more applications due to their high performance and their low production cost. This paper focuses on the windings inserted in the air gap of these motors and, in particular, to an original production technique that consists in printing them on a flexible printed circuit board. It theoretically shows that this technique, when coupled with an optimization of the winding shape, can improve the power density of about 23% compared with basic skewed and rhombic windings made of round wire. It also presents a first prototype of a winding realized using this technique and an experimental characterization aimed at identifying the importance and the origin of the differences between theory and practice.

A Simple Analog BLDC Drive Control for Electro-Mechanical Energy Storage System

Electro-Mechanical Batteries have important advantages compared with chemical batteries. High speed, slotless, external rotor, BLDC machines are used in these systems as Motor/Generator. It is used for converting the electrical energy to the rotational kinetic energy and vice versa. A bidirectional, variable frequency, variable amplitude, three phase BLDC drive needs for its operation in charge and discharge state. Generally, microprocessors are used for their control. But they are complex and expensive. In this paper, limitations, considerations, design and construction of a simple analog control circuit presents. Experimental results are verifying the design proses

Advanced BLDC machine drive with minimum torque ripple and maximum power

In this paper, the advanced control methods to minimise torque ripple and to maximise power density of a brushless DC motor/generator system. A simple and straightforward torque pulsation control method with copper loss minimisation for BLDC machines is presented first. Then, an optimal power control to maximise power density and minimise machine size and weight for BLDC machines is explained for generation modes. Overall, the proposed approaches can improve the performance of a BLDC motor/generator system.

Eddy current losses in permanent magnets of the BLDC machine

PurposeThis study aims to calculate eddy current losses in permanent magnets of BLDC machine in the generator mode of operation with no‐load.Design/methodology/approachStator slot openings and special design of the stator poles cause changes in the magnetic flux density changes in permanent magnets. The stator windings are not connected to an outer source and no currents flow in them. The induced eddy currents in permanent magnets are dependent solely on the stator geometry. Analytical approach to calculate the eddy current density distribution in permanent magnets is based on known distribution of magnetic flux density in the air‐gap of BLDC. The magnetic flux density distribution is obtained from magneto‐static finite element model of BLDC. For verification of analytical approach the eddy current density distribution in permanent magnets is also calculated by magneto‐transient finite element model of BLDC.FindingsThe eddy current losses in PM obtained with the FEM indicate additional heating of the BLDC machine at high rotational speeds even when it operates at no load. When some special stator designs (the side of the air gap) are needed, the losses in PMs and their heating increase.Research limitations/implicationsTo get more precise results, the proposed analytical method for eddy current losses calculation in PM should be further analyzed. More geometric parameters of the BLDC design should be introduced to analytical formulations, especially those which affect variations in reluctance.Practical implicationsWhen some special stator designs (the side of the air gap) are needed, the losses in PMs should be observed. This is particularly recommended at higher rotation velocities. Any kind of magnetic flux density change induces eddy currents and together with them also power losses. These losses give rise to additional heating of PM. With this, the temperature‐dependent working characteristic of PM (second quadrant of the B‐H curve) moves toward the coordinate origin point. The overall machine performance is reduced. The presented work gives the view about happenings in permanent magnets regarding induced eddy current losses. It is a useful tool for fast estimation and reduction of eddy current losses in PM due to stator geometry.Originality/valueThe value of the paper is the closed view about happenings in permanent magnets regarding induced eddy currents and the calculation of eddy current losses in rotor permanent magnets of BLDC due to stator design. The originality is in the analytical approach to calculate the eddy current losses based only on known magneto‐static flux density distribution in air‐gap of BLDC.