Gyeong-Jae Park

Interstellar Search Method With Mesh Adaptive Direct Search for Optimal Design of Brushless DC Motor

In this paper, a novel global search algorithm interstellar search method (ISM) and its hybridization with mesh adaptive direct search (MADS) are proposed. The ISM is a population-based algorithm that is suitable for multimodal function, due to its capability of finding points on the diverse basins of attraction in a short time. The hybridization with MADS supports the fast convergence on adjacent optima from the points that are discovered in global search using ISM. The effectiveness of ISM was validated through test functions, compared with genetic algorithm and particle swarm optimization. Last, the ISM was applied to the optimal design of brushless dc motor aimed for minimizing torque ripples, identified through finite-element analysis.

Numerical Design Compatibility of Induction Motor With Respect to Voltage and Current Sources

In this paper, the optimal driving point of induction motor is selected for guaranteeing torque production, which is fed by d-q current combination, and numerical design compatibility employing current source FEM is verified via comparison with the one employing voltage source method. In particular, vector control considering voltage and current constraints has been implemented numerically with FEM when selecting the optimal driving point. Moreover, comparative analysis is performed for the design results, such as magnetic saturation and iron loss, according to driving points selected in designing procedure. With the identified results, the design compatibility of FEM engaged with the current source is validated with comparison of the one obtained by FEM and equivalent circuit method engaged with the voltage source.

Design of IPMSM Applying V-Shape Skew Considering Axial Force Distribution and Performance Characteristics According to the Rotating Direction

Skew is a common method to reduce torque ripple and cogging torque. However, when skew is applied, unexpected axial force is produced. To reduce axial force, V-skew is used as one of the solutions. Specifically, when V-skew is applied, the magnetic flux distribution changes according to the rotating direction, which causes a difference in the performance. For the application in which the motor rotates in one direction, this phenomenon can be used to produce power with better quality torque and less losses. In this paper, the interior permanent-magnet synchronous motor (IPMSM) is designed by applying a V-skew to the stator, taking into consideration the manufacturing difficulties with applying a rotor skew to the IPMSM. The skew effect and the reduction of axial force are verified based on finite-element analysis. Moreover, torque, axial force, and losses are comparatively analyzed according to the rotating direction. All calculations and analysis are conducted based on 2-D and 3-D finite-element analysis.

Multi-domain co-simulation with numerically identified PMSM interworking at HILS for electric propulsion

In this paper, design and analysis of interior permanent magnet synchronous motor for electric vehicle bus propulsion is performed based on Finite Element Method. As the increase of the advanced application which requires precise control, the inverter is regarded as requisite for controlling electric machines. In addition multi-domain co-simulation is important to consider the inter-linking effect of the system as well as the conventional sinusoidal input analysis to investigate the characteristics of electric machines, specifically. Therefore, Multi-domain co-simulation is performed to consider the effect of inverter current, containing time harmonics, to the characteristics of interior permanent magnet synchronous motor in system circumstance. Simulated result is validated by comparing it with experimental result. Lastly, virtual driving test using Hardware-in-the-loop simulation is performed with co-simulated data to verify the reliability of multi-domain co-simulation model in virtual driving system.

Reducing computational time strategy for estimating core loss with spatial and temporal periodicity

For increasing system efficiency, proper loss estimation must be preceded. However performing core loss analysis on overall operation region is time consuming process. In this paper, reducing computation time strategy for estimating core loss with spatial and temporal periodicity is proposed. To validate whether this strategy is useful for complex motor configuration, it is applied to interior permanent magnet synchronous motors with various number of slot. Periodicity according to the different number of slot per pole per phase is considered as well. Lastly, core loss calculation results with full-period analyzed model, and strategy applied model are analyzed comparatively to verify its validity.

Design Characteristics of IPMSM With Wide Constant Power Speed Range for EV Traction

This paper presents study of design characteristics with wide constant power speed range (CPSR) for electric vehicle Propulsion. Through analysis of interior permanent magnet synchronous motor (IPMSM) control logic, design characteristic of extending CPSR is proposed. To achieve wide CPSR, center of voltage limit ellipse should be placed at cross point of current limit circle and d-axis. To analyze characteristic of voltage ellipse, four types of representative IPMSM rotor topologies are selected. Through rotor topology analysis, tendency of φ f and L ds parameters which decide center of voltage limit ellipse is analyzed. This paper also considers shifting of voltage limit ellipse center according to change in motor speed. Reflecting the result, this paper focuses on center of voltage limit ellipse position at maximum speed, because central coordinates of high-speed range determine characteristics of CPSR. Through the analysis result, this paper suggests direction of IPMSM design for wide CPSR.

Hybridization Algorithm of Fireworks Optimization and Generating Set Search for Optimal Design of IPMSM

Since design of electric machine concerns with numbers of design parameters, it is difficult and time consuming to obtain optimal design that satisfies all of requirements. For this reason, novel concept of optimization method, Fireworks Optimization (FO), is introduced in this paper. Since FO is an algorithm that is specialized in exploration, it is used combined with Generating Set Search (GSS) for optimal design of Interior Permanent Magnet Synchronous Motor (IPMSM).

Optimal Design and Validation of IPMSM for Maximum Efficiency Distribution Compatible to Energy Consumption Areas of HD-EV

Optimal design and validation combined with Finite Element Method (F.E.M) have been performed for realizing the maximum efficiency distribution of Interior Permanent Magnet Synchronous Motor (IPMSM) compatible to the Maximum Energy Consumption Areas (MECA) of Heavy Duty-Electric Vehicle (HD-EV). Particularly, the target energy consumption areas is specified with vehicle simulation. The dominant electromagnetic losses of IPMSM are numerically identified in association with F.E.M and optimization algorithm.

Numerical design and characteristic analysis of inverter-fed induction motor

In this paper, numerical design and characteristic analysis of induction motor fed by inverter are performed. For variable speed and high speed operation, induction motor is vector-controlled by Space Vector Pulse Width Modulation (SVPWM) inverter. By vector-controlling, input current of induction motor becomes controllable. Thus, on design and analysis of induction motor, the design method with current source, considering vector control and slip frequency characteristic, is proposed. Also, it is validated that current from SVPWM inverter contains an amount of time harmonics by Fast Fourier Transform (FFT). To consider it, characteristics of induction motor fed by SVPWM inverter, such as magnetic flux distribution, performance and loss, are analyzed and compared to those when it is fed by sinusoidal current source.

Data interpolation based on neural network for optimal design of interior PM synchronous machine

This paper proposes Neural Network (NN) based data interpolation and design optimization algorithm for an Interior Permanent Magnet Synchronous Machine. Data interpolation using NN is suitable for estimating the performance of an electric machine, because NN is approximate function for representing nonlinear data. To utilize NN as an approximate function, training process is required. After training process, optimal design of an electric machine can be found by applying search algorithm, such as Particle Swarm Optimization(PSO), Mesh Adaptive Direct Search(MADS) etc. This procedure does not demand any additional numerical analysis of electric machine based on finite element method, allowing search of optimal model in such short computation time.