Do-Kwan Hong

Fractional Slot Concentrated Winding PMSM With Consequent Pole Rotor for a Low-Speed Direct Drive: Reduction of Rare Earth Permanent Magnet

This paper deals with a 44pole-48slot fractional slot concentrated winding permanent magnet synchronous machine (FSCW PMSM) for a low-speed direct drive. Two different rotor topologies, a surface permanent magnet (SPM) rotor and a consequent pole (CP) rotor, are optimized and compared both analytically and experimentally. The experimental results confirmed that an FSCW PMSM with a CP rotor can achieve almost equivalent performance at the rated state when compared to an FSCW PMSM with an SPM rotor with 33% less permanent magnet material.

Optimum design of Maglev lift system's electromagnet for weight reduction using response surface methodology

Purpose – This paper aims to discuss the optimum design of a Maglev lift systems electromagnet to reduce the weight of the machine with constraint of normal force using response surface methodology (RSM).Design/methodology/approach – The optimum design of Maglev lift systems electromagnet for weight reduction is performed by using RSM. The magnetostatic analysis of Maglev lift systems electromagnet is performed by using ANSYS.Findings – The process is based on minimization of an appropriate objective function, while at each step the response is determined by the 3D finite element method (FEM).Research limitations/implications – It is necessary to compare normal force between the 3D FEM result and the experimental result of the manufactured model.Originality/value – The paper deals with the possibility of using the RSM for optimization of an electromagnet with a higher number of the design variables.

Application of fractional factorial design for improving performance of 60W transverse flux linear motor

This paper presents an optimum design procedure of permanent-magnet-type 60W transverse flux linear motor to reduce the weight of the machines with the constraints of thrust and detent forces using fractional factorial design and response surface methodology (RSM). RSM is well adapted to make the analytical model of minimum weight with constraints of thrust and detent forces, and it enables objective functions to be easily created, and a great deal of computation time can be saved. Therefore, the usefulness of this method is verified through the comparison of the performances of the optimal model and those of the initial model.

Unbalance Response Analysis and Experimental Validation of an Ultra High Speed Motor-Generator for Microturbine Generators Considering Balancing

The objective of the present study was to deal with the rotordynamics of the rotor of an ultra-high speed PM type synchronous motor-generator for a 500 W rated micro gas turbine generator. This paper introduces dynamic analysis, and experiments on the motor-generator. The focus is placed on an analytical approach considering the mechanical dynamic problems. It is essential to deal with dynamic stability at ultra-high speeds. Unbalance response analysis is performed by calculating the unbalance with and without balancing using a balancing machine. Critical speed analysis is performed to determine the operating speed with sufficient separation margin. The unbalance response analysis is compared with the experimental results considering the balancing grade (ISO 1940-1) and predicted vibration displacement with and without balancing. Based on these results, a high-speed motor-generator was successfully developed.

An Analytical Approach for a High Speed and High Efficiency Induction Motor Considering Magnetic and Mechanical Problems

This paper deals with the analysis techniques of a high speed and high efficiency 10 kW, 30,000 rpm rated induction motor. The induction motor has been analyzed by time-varying magnetic finite element method and the test results show that there is a possibility that the motor could be used in a high speed spindle system application. All analysis techniques are introduced to develop a high speed and high efficiency induction motor made by copper die casting. The analysis techniques are composed of magnetic analysis considering losses and input current (PWM and sinusoidal), structural analysis of rotor and stator, 3-D rotordynamic analysis and 3-D CFD. All performances of the prototype are successfully verified.

Dynamic simulation of radial active magnetic bearing system for high speed rotor using ADAMS and MATLAB co-simulation

A co-simulation using ADAMS and MATLAB/ Simulink is proposed for the dynamic simulation of high speed rotating flexible rotor supported by active magnetic bearings. The controller and actuator of AMBs are modeled in MATLAB/Simulink and the plant model of the rotor is implemented in ADAMS software. A decentralized proportional - integral - derivative (PID) control is used as main position regulator. The electromagnetic actuator is modeled as linearized spring with constant position stiffness and current stiffness. The current amplifier is modeled as proportional current controller which drives electromagnet coils with constant DC voltage. The rotor is modeled as flexible body in ANSYS software and the ADAMS gives motions and mechanical constraints to this body, finally completes rotating flexible rotor model supported AMBs. The ADAMS plant model is incorporated to MATLAB/ Simulink as a s-function, and MATLAB do the simulations. In the co-simulation results, run-out values of the constantly rotating flexible rotor is calculated numerically, which is not reported in rigid body rotor dynamics.

Optimum design of an outer rotor and spoke type direct-drive machine for turret applications with large diameter

This paper deals with the optimum design focused on an LHS (Latin hypercube sampling) experiment with the many design variables of a developed motor and comparison of the optimum algorithm. The effective design variables are selected by screening and analysis of means (ANOM). In this paper, the optimum design is achieved by using the comparison response surface methodology (RSM) with the genetic algorithm (GA) method as the multiobjective optimum design. The torque ripple ratio is satisfied with a design goal within 3%. Therefore, multiobjective optimum design is considered between average torque and efficiency. The simulation results are compared with the experiment and show a deviation below 5%.

Magnetic field and rotordynamic analysis of 30 krpm 220 kW rated high speed motor for blower supported magnetic bearing

This paper introduces the applied AMB(Active Magnetic Bearing) System supported by magnetic bearing which is controlled. The system needs component design technique for develop AMB System. Magnetic field analysis, PID control and 3D rotordynamic analysis of AMB is performed. The required performance of motor is a 220 kW, 30 krpm high speed motor. The 3D rotordynamic analysis considering magnetic bearings are simulated to find the critical speed of rotor by Cambpell diagram. The analysis shows that the critical speed of the rotor is higher than operating speed with sufficient separation margin. All the performances of the AMB high speed motor prototype are verified successfully

The optimum design of a moving PM-type linear motor for resonance operating refrigerant compressor

Moving Permanent Magnet (PM) type Longitudinal Flux Linear Motors (LFLMs) are electromagnetic devices which can develop directly powerful linear motion. This paper deals with an effective analysis of PM-type LFLM by Finite Element Method (FEM) and optimum design for lightweight. This paper presents the statistical optimum design of PM-type LFLM to reduce the weight of a moving PM-type linear actuator with the constraint of avg. thrust force using the penalty method with characteristics function and kriging interpolation method. The contribution and effect of the each design variable on the characteristic function is evaluated by the analysis of means (ANOM) and optimum design set is determined. The generalized reduced gradient (GRG) algorithm is adopted in kriging model. Therefore, it is expected that the proposed optimization procedure using penalty method and kriging interpolation method can be easily utilized to solve the optimization problem with constraint of electric machine.

Design, Analysis, and Experimental Validation of a Permanent Magnet Synchronous Motor for Articulated Robot Applications

Based on the base module of Universal Robotics, this paper deals with a 16-pole, 18-slot fractional-slot concentrated-winding permanent magnet synchronous machine (PMSM) for articulated robot applications considering several pole-slot combinations and using an optimum design. The selected PMSM considering the pole-slot combination is optimized and compared both analytically and experimentally. The experimental results confirmed that the proposed PMSM can achieve improved performance at the rated state. Repeatability test results of the proposed smart actuator with a link-attached sphere-mounted retroreflector sensor met the goal of within