Sarbajit Paul

Korea Electrotechnology Research Institute-KERI · Electric Machine and Drive System Research Center

The Korean government is facing growing concern over the increasing levels of fine dust. A significant contribution to this problem comes from coastal vessels. To mitigate this, an electric ship propulsion system has been proposed as a solution to reduce air pollution. The application of a fully electric propulsion system in a ship is challenging d...

This paper proposes the design process of a field modulated (FM) permanent magnet linear actuator for the 5-axis gantry robot system by investigating the parameters effecting working harmonics. The detailed design process using magnetic gearing effect has been developed considering the magnetic equivalent circuit (MEC) and finite element analysis (...

This paper presents a critical review of traction motors used for distributed traction (DT) applications in high-speed railways (HSR). The motor topologies that can be used for DT-HSR are presented. The advantages and disadvantages of each motor in terms of structural and electromagnetic performance are discussed from the perspective of motor desig...

This paper proposes a detailed mathematical dqn axes dynamic modeling of a double saliency flux modulated permanent magnet linear synchronous motor (DS FM-PMLSM) used as the linear actuator for the five-axis gantry robot system to study thrust ripple characteristics. To derive the model, the machine double saliency is considered by analyzing the ef...

An initial mover position (IMP) detection algorithm for a dual saliency flux modulated permanent magnet linear motor (DS FM-PMLSM) for a 5 axis gantry robot has been proposed in this proposed work. The proposed IMP algorithm uses the saliency of the proposed machine which results in the inductance variation and checks the change in the inductance b...

This paper proposes the design and analysis of a flux modulated (FM) permanent magnet linear actuator for the long track gantry robot system used to detect fire hazards in electric energy storage system (ESS). A detailed design framework for the FM-linear actuator inspired by the magnetic gearing effect is proposed which includes the selection of s...

The aim of this proposed work is to develop a computationally efficient and accurate AC winding loss analysis model for the traction motors for use in high-speed railways (HSRs). The goal of the model is to be able to study AC winding loss under both sinusoidal and pulse width modulated (PWM) inverter voltage sources. The traction motor model consi...

The dissertation presents the design and analysis of a consequent pole flux modulated permanent magnet linear synchronous motor (CP FM-PMLSM) for long track application. Usually, for linear actuation applications in industry, surface permanent magnet linear synchronous motors (SPMLSM) are widely used. However, due to the presence of the permanent m...

A superior model of a novel electromechanical actuator for the computer numerical controlled (CNC) lathe has been proposed. The proposed actuator aims to achieve a high thrust of 50 kN and a spindle speed of 6000 RPM. Furthermore, a ball screw drawbar is used in the proposed model to reduce friction losses and improve mechanical efficiency. The clu...

This paper proposes the design process and performance of an Urban Water-pipeline Energy Harvester (UWEH) System. The UWEH system design is broadly divided into two parts, namely, the electromagnetic and mechanical subsections modeling. The electromagnetic modeling includes the selection, design, prototyping and performance testing of a 65-kW perma...

Model order reduction (MOR) is considered as a good alternative to reduce the computational scale for electromagnetic problems. The aim of this work is to introduce the use of dynamic mode decomposition (DMD) as a promising tool for MOR to analyze its effectiveness in creating a fast model-based design platform for the permanent magnet motor design...

This work presents a coursework design process to study the fugitive dust generation and detection method in South Korean Cities. The work is broadly classified into two parts, namely, designing of a software-based virtual platform to study the fugitive dust generation sites i.e the construction sites in a 3D computational fluid dynamics (CFD) envi...

This paper proposed the nonlinear modeling and a full-scale testing method for an electromagnetic energy harvester (EMEH) used to power-up a vibration de-icing robot used in power transmission line. The aim of the proposed work is to have an detailed analytical model of the EMEH on MATLAB environment which is capable of considering the EMEH ferroma...

This paper proposes a 65kW rim-driven direct drive flux concentrated PM synchronous generator (FCPMSG) used in Urban water pipeline energy harvester (UWEH) system. The proposed UWEH system plans to use hydraulic bearing, thus a balanced radial force topology should be selected with high electromagnetic performance. Considering the hydraulic bearing...

The present invention relates to a foldable drone which includes a body having a rotor installed therein to be relatively rotated at a predetermined angle, such that a plurality of rotors are unfolded and spaced apart at predetermined intervals when using the drone and are folded to minimize volume when not in use to increase portability and durabi...

본 발명은 도전율이 자성체에 비해서 높은 알루미늄과 같은 도체를 활용하여 도체와 자성체 또는 도체와 비자성체의 조합으로 필요한 발열을 확보하여 매우 적은 무게로 송전선로의 빙설을 방지 또는 제거할 수 있는 송전선로의 빙설 제거장치에 관한 것으로, 본 발명에 따른 송전선로의 빙설 제거장치는, 송전선로의 외측을 둘러싸도록 설치되는 본체부; 상기 본체부에 원주방향을 따라 간격을 두고 설치되며, 송전선로와 나란하게 배치되어, 송전선로를 따라 흐르는 전류에 의해 와전류를 발생하여 발열하는 도전성 재질로 된 복수의 와전류유도부재; 및 상기 본체부의 내측면과 송전선로의 외측면 사이에 설치되는 절연성 재질의 절연부재를 포함한다

To remove the system level problems associated with the traditional hydraulic operated lathe, the proposed work presents the design of a highly efficient feedback control enabled built-in motor clutch coupled electric driven lathe system. The system modeling is discussed with prototyping and testing of the electric driven lathe to confirm its perfo...

This paper presents design and comparative study of high torque coaxial permanent magnet couplings (CPMC) for the use in a tidal current generation (TCG) system. Two different models such as a radial flux-CPMC (RF-CPMC) with magnet retaining rings and a flux concentrating-CPMC (FC-CPMC) with inner and outer rotor yoke changed by retaining rings are...

This paper proposes the model-based design methodology of a 60-kW direct drive variable speed permanent magnet synchronous generator (PMSG) used in an urban water pipeline energy harvesting system. The whole study aims to design the PMSG considering different system parameters of the energy harvesting system such as the mechanical parameters, elect...

This paper proposes the design and driving mechanism of a single drive motor integrated electromechanical actuator system for the application in computer numerical control (CNC) lathe machines. The electromechanical actuator is designed in such a way that it can replace the conventionally used hydraulically powered headstocks of the lathe machine....

This paper proposes two novel airgap profile designs and distributed airgap arrangement scheme for reduction of winding and thermal losses in high frequency current transformer (HFCT) sensors. The novel airgap profiles namely, zigzag and stepped airgap profiles are proposed to reduce fringing flux around the winding conductors. Moreover, to decreas...

The present work proposes the design process of a novel dualcore electromagnetic energy harvester (EMEH) for the use in a deicing robot, used on power transmission lines. The EMEH is designed with a dual-core where Silicon (Si) and Nickel (Ni) steels have been used in order to take advantage of both materials characteristics. An analytical model fo...

Model order reduction (MOR) is considered as a good alternative to reduce the computational scale for quasi-magnetostatic problems. The aim of this work is to introduce the use of dynamic mode decomposition (DMD) as an promising tool for MOR to analyze its effectiveness in solving quasi-magnetostatic problems. Using a singualr value decomposition (...

Axial-flux permanent magnet synchronous machines (AF-PMSM) using PCB windings are attracting interest due to an increased demand for machines with thinner geometries. A critical element is the choice of its PCB winding which should ensure high performance characteristics with an efficient use of the PCB surface. However, there is a gap in the knowl...

This paper proposes the design of a linear magnetic position sensor (LMPS) to detect the mover position of the permanent magnet linear synchronous machines (PMLSM). The working principle of the LMPS is based on the well-known Hall- Effect. The Hall-Effect based design of LMPS is considered because it provides a low cost and relatively harsh environ...

본 발명은 기존의 2차원 헤밀턴 주기(Hamiltonian cycle)를 이용한 트랙 적층방법이 반경방향인 것을, 배치되는 트랙이 축방향으로 적층되도록 배치하여 엔코더의 반경방향 크기를 제한하면서 엔코더의 분해능을 향상시키기 위한 광학식 절대 엔코더의 구조와 이를 통해 절대 위치 정보를 검출하는 방법을 제공하기 위한 것으로서, 빛 통과 섹터와 빛 가림 섹터로 나누어진 적어도 2개 이상의 미소 트랙(track)이 축 방향으로 적어도 2층 이상 적층하여 배치된 2차원 원형 패턴을 갖는 중공 실린더와, 상기 미소 트랙(track)에 빛을 조사하는 광 신호 발생부와, 상기 광 신호 발생부에서 발생한 빛이 미소 트랙에 설치된 빛...

An electromangetic energy harvester (EMEH) is proposed in the present paper which is designed considering the power requirement of an ice removing device used to remove the ice and snow from power transmission lines. This work addresses the influence of the material characteristic of the magnetic core to achieve the required power. Three different...

This work proposes a dual-core electromagnetic energy harvester for a deicing device on power transmission lines with a detailed analytical expression of the induced voltage. Also two unique air gap designs have been proposed for low reluctance path using finite element analysis. The results show the superiority of proposed models over the conventi...

This paper presents design and a comparative study of a high torque coaxial permanent magnet coupling (PMC) for the use in a tidal power plant. Two different models are analyzed to find the best model under certain design constraints to achieve a minimum torque of 1.2kNm with reduced radial force.

두 회전자의 기계적인 접촉 없이 토크를 전달할 수 있는 장치인 반경방향 자기 커플링(Radial Permanent Magnetic Coupling, RPMC)은 기계식 커플링에 비해 진동과 소 음이 작고 마찰에 의한 기계적인 손실이 없다. 또한 과도한 힘 발생 시 기어의 이가 부러지는 기계식 기어와 달리 자기 커플링 은 자체 슬립이 생겨 기기를 보호하기 때문에 유지보수 비용에 대한 절감 효과가 크다. 이러한 특징으로 인해 인체 또는 환경 에 유해한 유체로 이루어진 장치 밀폐 시스템과 펌프 구동 시 스템 등에서 사용된다. 그러나 RPMC는 반경 방향 힘에 의해 접착되어 있던 영구자석이 백요크와 탈착되는 현상이 발생하기 도...

This work proposes a dual core electromagnetic energy harvester for a deicing device on power transmission lines. At first a dual core electromagnetic energy harvester (EMEH) is designed using silicon steel and permalloy as core materials. Secondly, two unique air gap designs have been proposed for low reluctance path using 2D finite element analys...

A novel approach to realize a high-resolution absolute encoder with compact disk size for the application in a light weight robotic arm modular joint is proposed in the present research. Firstly, the high resolution coded disk of the absolute encoder is designed using graph theory based Hamiltonian cycle. Unlike the traditional one-dimensional bina...

Axial-flux permanent magnet synchronous machines (AF-PMSM) using PCB windings are attracting interest due to an increased demand for machines with thinner geometries. A critical element is the choice of its PCB winding which should ensure high performance characteristics with an efficient use of the PCB surface. However, there is a gap in the knowl...

This paper presents a novel parametric design analysis of the magnetic sensor module used to find mover positions in linear motors. The proposed framework utilizes a computationally inexpensive proper orthogonal decomposition (POD)-dynamic mode decomposition (DMD)-based model order reduction (MOR), coupled with a multiparameter moment matching meth...

The problem of the computationally efficient analysis of the electromagnetic system with nonlinearity is considered in the proposed work. Unlike the previously proposed proper orthogonal decomposition (POD) based model order reduction (MOR), the proposed method based on the dynamic mode decomposition (DMD) works well even under the highly nonlinear...

This paper presents a new type of absolute rotary encoder system based on the affine ndigit N-ary gray code. A brief comparison of the existing encoder systems is carried out in terms of resolution, encoding and decoding principles and number of sensor heads needed. Using the proposed method, two different types of encoder disks are designed, namel...

The present invention relates to an apparatus and a method to determine the initial position of a permanent magnet type synchronous motor in order to estimate the initial position of the permanent magnet type synchronous motor by using a detected relative position while not relying on load conditions without a stimulation sensor. The apparatus comp...

This paper presents a design approach for a magnetic sensor module to detect mover position using the proper orthogonal decomposition-dynamic mode decomposition (POD-DMD)-based nonlinear parametric model order reduction (PMOR). The parameterization of the sensor module is achieved by using the multipolar moment matching method. Several geometric va...

This paper presents a parametric study of the electric motor based on model order reduction (MOR). To include the effect of the parameter into the reduced model, multipolar moment matching method is used. Firstly, the high dimensional model is parameterized using the multipolar moment matching method based on Taylor series expansion and then proper...

This paper presents an accurate initial pole position estimation method for a surface mounted permanent magnet synchronous motor without the use of pole sensors. To estimate the initial pole position, the proposed method uses the concept of reference frame. In this method, three torque commands, separated by 45 degree electrically from each other a...

This paper presents an accurate initial pole position estimation method for a surface mounted permanent magnet synchronous motor without the use of pole sensors. To estimate the initial pole position, the proposed method uses the concept of reference frame. In this method, three torque commands, separated by 45 degree electrically from each other a...

This paper presents a proposal to design the absolute encoder disk based on n digit N-ary cyclic gray code. The n digit N-ary cyclic gray code is generated using affine transformation. Based on the concept of the n digit N-ary cyclic gray code, two types of the coded tracks were designed, namely, Nary cyclic color coded track and N-ary cyclic gray...

Recently, PMLSM are used in many areas of manufacturing and automatic transfer system for flat panel display and factory automation. For accurate motion control and smooth startup, precise initial pole position (IPP) information of the PMLSM is found by using pole sensors [1]. However mechanical error in the installation of pole sensors results err...

A new method to detect the mover position of a linear motor is proposed in this paper. This method employs a simple cheap Hall Effect sensor-based magnetic sensor unit to detect the mover position of the linear motor. With the movement of the linear motor, Hall Effect sensor modules electrically separated 120° along with the idea of three phase bal...