Static characteristics of the double rotor switched reluctance motor

Static measurement characteristics of the double rotor switched reluctance motor developed on the basis of double salient dual air-gap structure is put forward in this paper. The reduction of the air - gap length of the conventional machine is constrained by the mechanical intolerances that inherit the torque generating capability. Therefore there is always a limitation on the air-gap length. However, with reduced air-gap length the magnetic flux control is improved with the aid of dual air-gap structure inside the machine. Analytical and finite element analysis is carried out to investigate the magnetic field distribution at different rotor positions and with different currents. The static torque characteristics derived from the fabricated model is compared with that of the finite element methods and analytical methods. The measurement results are in closer agreement with the analytical and simulation. Motor constant square density is used for the performance evaluation of the proposed machine and the characteristics are evaluated and compared by all three methods presented

Initial progress and possible improvement of e-cutter linear actuator development

Currently, palm oil has become the most consumed vegetable oil type. This is due to an awareness of the effect Trans Fat has on human health. Therefore, increasing productiveness is a crucial factor to ensure its continued availability as a product in the marketplace. One of the processes that should be improved to increase productivity is harvesting. The Malaysian Palm Oil Board (MPOB) has put a lot of effort into developing a mechanized harvesting tool called the Cantas™. This efficient tool has been shown to increase oil palm harvesting productivity by a factor of 3. However, Cantas™ is ineffective at harvesting oil palm fruit in trees taller than 8m. Therefore, a new tool called the E-Cutter was introduced. In this paper, the development progress of specifically the E-Cutter’s linear actuator part was discussed. The previous type of linear actuator for the E-Cutter is also mentioned. Improvement in the planning and design target of the linear actuator is also addressed. The potential linear actuator structure and type is also identified

Structure optimization of a 6 slot 8 pole permanent magnet linear motor

Palm oil has become the most consumed vegetable oil. In order to ensure its sustainability, the productivity of oil palms is targeted to increase by about 3.5% each year. Mechanization is one method to improve the oil palm productivity. Most activities in the oil palm process have been mechanized, and the mechanization of the harvesting process still need to be established. Tools to this end have been introduced by the Malaysian Palm Oil Board (MPOB) in Malaysia with the introduction of the Cantas™, however, due to their operational limitations, the E-cutter was later introduced. In this paper, the design of the E-cutter’s actuator is discussed. The design targets of the actuator are also briefly explained. In the end, an E-cutter’s actuator with 218 N of average thrust, Fave and a total weight, W, of 1.8 kg has been designed. The performance of the E-cutter’s actuator is also compared to a commercialized linear motor to prove its high performance

Optimizing the magnetic dimensions for maximum thrust in high density transverse flux linear motor

This paper describes the optimization of the magnetic dimensions for maximum thrust for a High Thrust Density Transverse Flux Linear Motor (HDTFLM). HDTFLM is a novel structure with combination of a typical High Thrust Density Linear Motor (HDLM) and Transverse Flux Linear Motor (TFLM) structure. The magnetic circuit of HDTFLM is different compared to conventional three phase linear motor because it has independences magnetic circuit on each phase. The optimization of maximum thrust is achieved by varying the thickness and height of the permanent magnet. This paper reports the optimized dimensional values for the HDTFLM structure for maximum thrust development

Positioning system for sensor less linear DC motor

Linear motor has gain popularity as linear motion drive in office and factory automation which provides an alternative method to conventional rotary motor. Chip mounting is one of linear motor applications especially for Linear DC Motor (LDM). Displacement sensor which is normally used for positioning on the system, made the system expensive. This paper discusses the application of sensor less on positioning system for LDM. A spring is used to determine the position, while the spring displacement which is proportional to the thrust was produced by the motor. The thrust itself can be controlled by controlling the current supplied to the motor. Therefore, the positioning of LDM can be controlled by varying the current value. The approach used in this paper is to control the current is by manipulating various pattern of Pulse Width Modulation (PWM) signal. As a result, the settling time less than 32ms for 10mm positioning has been achieved

Thrust Optimization of Linear Oscillatory Actuator Using Permeance Analysis Method.

This paper describes thrust optimization of linear oscillatory actuator (LOA). The objective of the optimization is to obtain the highest as possible thrust at restricted weight of LOA in order to ensure it equipped with adequate thrust and mobility features. In this research, the LOA is aim to have a starter thrust higher than 200 N while having total of weight lower than 2.0 kg. The thrust of LOA was optimized by using permeance analysis method (PAM). The thickness of the permanent magnets and the height of coils have been varied at different fixed total of radius of LOA in order to obtain the optimized structure. The optimized structure of LOA was decided by using two different methods. The first method is by evaluating the each point of the calculation output. The second method is by using generic algorithm. Both output of these method giving a different result in term of LOA PM's thickness however having similar thrust characteristics. The FEM and measurement results were used to verify the PAM output. Consequently, the LOA has been designed with optimum parameters which having value of starter thrust of 245 N and the total weight is 2.0 kg

Basic characteristics of double stator slot-type permanent magnet generator

This paper discusses the basic characteristics of a double stator slot-type permanent magnet generator (DS-PMG). The PMG was basically operated in a single-phase and the flux direction in the air gap was radial. It was developed to optimize the magnetic flux linkage in a single-pole PMG. Simulation with the Finite Element Method (FEM) and calculations were used to analyze the PMG’s characteristics. In addition, the performance of the PMG prototype was evaluated to ensure the simulation results were accurate. The DS-PMG had a low Total Harmonic Distortion (THD) of 6% and high efficiency of 80% at the rated speed of 3000 rpm. Here, THD is a comparison of the fundamental waveform to its harmonic content. Its output power was three times that of the single PMG

Performance comparison of spoke and hollow-rotor permanent magnet generator for small energy harvesting application

This paper presents performance comparison between spoke type and hollow-rotor permanent magnet generator (PMG) that could be used for low speed energy harvesting application. In this application, the requirement for such generator would be higher power density due to the limitation of space, volume and weight. The drawback of spoke type PMG is the flux leakage at end of the permanent magnet that embedded inside the rotor. Meanwhile, the hollow-rotor PMG introduces a hollow segment that obstructs the flux from flowing at the end of the permanent magnet. This new arrangement maximizes the energy that contributes by the permanent magnet. The objective of this paper is to compare the performance of both PMG in term of output power and speed at various load condition. In this research finite element analysis is used for modelling and simulating the PMG performance. For final comparison, power density is used for evaluating the best performance and the result shows that the hollow-rotor topology has higher power density compared to spoke type PMG. In the end, this paper provides an overview about the advantage of hollow-rotor topology that could be used for small energy harvesting application

Torque characteristics of small size single and double stator brushless permanent magnet motor

The paper presents the torque characteristics of small size single and double stator of brushless permanent magnet DC motor (BLDC). The effect of different magnetic circuit towards the torque characteristic of permanent magnet motor is presented. Three different magnetic circuits are modeled using Finite Element Analysis (FEA) tool to simulate the torque and cogging characteristics of the motor for the same size values. Total harmonic distortion (THD) of the torque is used to evaluate the characteristics of the motor. Based on the result, it shows that double stator type BLDC produced higher torque compared to single stator type BLDC. However, the serial and parallel of magnetic circuit affect the cogging characteristics of the motor. Conclusively, the paper contributes in term of guidance and suggestion for magnetic circuit selection before designing a BLDC