Heui-Joo Park

Development of a 100 hp synchronous motor with HTS field coils

A 3-phase, 100 hp, 4 pole, 1800 rpm superconducting synchronous motor built and tested in Korea Electrotechnology Research Institute(KERI). This machine consists of HTS rotor and air-core stator. The HTS field windings are composed of the double-pancake coils wound with AMSCs stainless steel-reinforced Bi-2223 tape conductor. These were assembled on the support structure and fixed by a bandage of glass-fiber composite. The cooling system is based on the heat transfer mechanism of the thermosyphon by using GM cryocooler as cooling source. The cold head is in contact with the condenser of a Ne-filled thermosyphon. The rotor assembly was tested independently at the stationary state and combined with stator. The open circuit, no-load, and short circuit characteristic were obtained. Also, load tests in motor mode driven by inverter and generator mode connected to resister load bank were conducted. This paper will present design, construction, and experimental test results of the 100 hp HTS machine.

Status of HTS Motor Development for Industrial Applications at KERI & DOOSAN

This work is development of HTS motor at DOOSAN heavy industry and Korea Electrotechnology Research Institute in Korea, and is sponsored by DAPAS program which is supported by Korean government. The final aim of the project is realization of HTS motor in the field of industry such as large driving pumps, fans and compressors for utility and industrial environments. In the first phase (2001-2004), 100 hp HTS motor was developed in order to implement the preliminary technology for the large applicable HTS motor. All of the performance characteristics are well met to the designed ones. In second phase (2004-2007), 1 MW HTS motor is developed for the purpose to fully represent the design and manufacturing issues for the larger capacity machine. The machine is 2 pole and 3600 rpm, and all of the components are completely manufactured. This machine is now under assembly. This paper summarizes the status of 1 MW HTS motor development, such as design, construction, and experimental test results.

Effect of Synchronous Reactance and Power Factor on HTS Synchronous Machine Design and Performance

Synchronous reactance is an important parameter of synchronous rotating machine because it affects on the machine output capacity, voltage variation and steady-state stability. The superconducting synchronous rotating machine has very small synchronous reactance about 1/5 of the conventional synchronous machine. This reason comes from the fact that the superconducting rotating machine is air-cored structure. In this paper, it is estimated how much this synchronous reactance has influences on many design parameters of superconducting synchronous machine such as machine volume and weight, efficiency, voltage variation and so on. In the case of a synchronous motor, the power factor can be adjusted according to the excitation voltage. This paper also deals with the effects of power factor on the design parameters and the performance of a HTS (High-temperature Superconducting) synchronous motor. This kind of analysis was used to design 1 MW class HTS motor

Development of a MW-Class 2G HTS Ship Propulsion Motor

This paper describes the design and fabrication progress of a MW-class 2G high-temperature superconductor (HTS) motor for the ship propulsion application at Doosan Heavy Industries and Construction. The most important component of an HTS motor is the rotor, which is composed of HTS coil, torque disk, damper, and hollow shaft. The HTS rotor using hastelloy-based 2G HTS coils was designed and built. Open-circuit and short-circuit characteristics of the superconducting motor were investigated and compared with the analysis results at reduced excitation to verify the design. Preliminary testing of a 2G HTS motor has been conducted at a few hundred kW as per the design. Through these results, we verified that most of the design criteria could be satisfied.

Status of HTS Motor Development in Korea

This work is development activities of HTS motor at DOOSAN heavy industry and Korea Electrotechnology Research Institute in Korea, and is sponsored by DAPAS program which is supported by Korean government. The final aim of the project is realization of HTS motor in the field of industry such as large driving pumps, fans and compressors for utility and industrial environments. At present time, 1 MW HTS motor is developed for the purpose to fully represent the design and manufacturing issues for the larger capacity machine. The machine is 2 pole and 3,600 rpm, and all of the components are completely manufactured. Preliminary performance test of this machine was already finished, and is ready for long run reliability test. This paper summarizes the status of 1 MW HTS motor development, such as design, construction, and experimental test. As a next step target, ship propulsion motor is considered, so that middle class such capacity as 5 MW, and large class such capacity as 20 MW HTS motor are conceptually designed. The outline and conceptual design results for homopolar and air-core type superconducting motor which apply to low-speed high power pod propulsion application are discussed i n this paper.

Design considerations for 1 MW class HTS synchronous motor

A 1 MW class superconducting synchronous motor is designed considering several conditions such as superconducting wire length, machine efficiency and size. As the machine is larger and larger, the superconducting machine shows the advantages more and more over the conventional machines. Although the advantages at 1 MW rating are not so great, the design approach to get an appropriate result would be very helpful for larger superconducting synchronous machine design. Major design concerns are focused on reducing expensive Bi-2223 HTS (High Temperature Superconducting) wire which is used for superconducting field coil carrying the rating current around 30 K (-243/spl deg/C) while the machine efficiency is higher than conventional motors or generators with the same rating. Furthermore, some iron-cored structure is considered to reduce the HTS wire requirement without bad effect on machine performances such as sinusoidal armature voltage waveform, synchronous reactance and so on.

An introduction to the design and fabrication progress of a megawatt class 2G HTS motor for the ship propulsion application

This paper introduces the design and fabrication progress of a megawatt class 2G high temperature superconductor (HTS) motor for the ship propulsion application at Doosan Heavy Industries and Construction. The purpose of this 2G HTS propulsion motor is to launch the business area for marine applications such as surface ship, submarine, merchant ship etc. The principles and interpretation of the magnetic field for 2G HTS motor and permanent magnet type motors are similar on the basis of 3D design and production. The most important component of an HTS motor is the rotor, which is composed of HTS coil, non-ferrous metal, torque disk, damper, and hollow shaft. A HTS rotor using hastelloy-based 2G HTS coils was designed and built. Open-circuit and short-circuit characteristics of the superconducting motor were investigated and compared with the analysis results at reduced excitation to verify the design. Preliminary testing of a 2G HTS motor has been conducted at a few hundred kilowatts as per the design. Through these results, we anticipate that most of the design criteria can be satisfied. However, we have faced several issues during the testing of the motor and these issues need to be resolved in order to take the design further.

Design and Analysis of 1 MW Synchronous Machine via 3D Magnetic Field Calculation

A 1 MW class superconducting synchronous rotating machine has been designed as a draft based on 2-dimensional (2D) magnetic field distribution considering several conditions such as superconducting wire length, machine efficiency, size and so on. By the way from 2D design it is not possible to consider the effect of end coils and end portions of stator iron yoke especially in superconducting machine with air-cored structure which increases magnetic field difference between 2D and 3D analysis. In this paper electrical design based on the 3D magnetic field distribution is conducted to get more proper design result and reduce design errors from 2D design approach. As the machine has larger capacity, the superconducting machine will show the advantages more and more over the conventional machine. Although the advantages at 1MW rating are not so great, the 3D design approach to get more optimized result would be very helpful for larger superconducting synchronous machine design. Through 3D analysis such as EMCN (equivalent magnetic circuit network) method and Flux-3D FEM (finite element method), we could get smaller machine size, higher efficiency, and smaller Bi-2223 HTS (high temperature superconducting) wire length than the 2D design result. Moreover influence of an important parameter, synchronous reactance, has been analysed on the machine performances such as voltage variation and output power.

Economic Feasibility Study of an HTS DC Induction Furnace

Conventional induction furnaces have been in operation in nonferrous metal and related industries with poor energy efficiencies of only 50-60%. Moreover, the efficiency of atmosphere furnace, one of the various heating facilities for metal billets, is about 20%. For ensuring high energy efficiency in these heating furnaces fields, as one of the better counterplans, a novel dc induction heating method using HTS magnets has been suggested. To realize the HTS dc induction furnace (HIF) in the industrial field, the most important issue is to guarantee economic favor in comparison with two different types of conventional furnaces. In this paper, we performed an economic feasibility study of an HIF in terms of electricity fee minimization. Net present value, internal rate of return, and pay-back period methods were used to evaluate the investment returns of an HIF. All indicators related to direct benefits were calculated and analyzed for finding economic feasibility. The analysis results will be applied to decision making process for the commercialization of the HIF.

Loss analysis of a 1 MW class HTS synchronous motor

The HTS (High-Temperature Superconducting) synchronous motor has advantages over the conventional synchronous motor such as smaller size and higher efficiency. Higher efficiency is due to smaller loss than the conventional motor, so it is important to do loss analysis in order to develop a machine with higher efficiency. This paper deals with machine losses those are dissipated in each part of a HTS synchronous motor. These losses are analyzed theoretically and compared with loss data obtained from experimental results of a 1 MW class HTS synchronous motor. Each machine loss is measured based on IEEE 115 standard and the results are analyzed and considered based on the manufacturing of the test machine.