• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.1
• /
• pp.71-80
• /
• 2007

A control approach for the sensorless speed control of interior permanent magnet synchronous motor(IPMSM) based on adaptive integral the binary is proposed. With a main loop regulator and an auxiliary loop regulator, the binary observer has a property of the chattering alleviation in the constant boundary layer. However, the width of the constant boundary limits the steady state estimation accuracy and robustness. In order to improve the steady state performance of the binary observer, the binary observer is formed by adding extra integral augmented switching the hyperplane equation. By mean of integral characteristics, the rotor speed can be finely estimated and utilized for a sensorless speed controller for IPMSM. The proposed adaptive integral binary observer applies an adaptive scheme, because the parameters of the dynamic equations such as the machine inertia or the viscosity friction coefficient is not well known and these values can be easily changed generally during normal operation. Therefore, the observer can overcome the problem caused by using the dynamic equations, and the rotor speed estimation is constructed by using the Lyapunov function. The experimental results of the proposed algorithm are presented to demonstrate the effectiveness of the approach.

• Proceedings of the KIEE Conference
• /
• 2006.07b
• /
• pp.925-926
• /
• 2006

This paper presents a sensorless speed control of an interior permanent magnet synchronous motor using an adaptive integral binary observer and fuzzy logic controller. In view of composition with a main loop regulator and an auxiliary loop regulator, the binary observer has a property of the chattering alleviation in the constant boundary layer. However, the steady state estimation accuracy and robustness are dependent upon the width of the constant boundary. In order to improve the steady state performance of the binary observer, the binary observer is formed by adding extra integral dynamics to the switching hyperplane equation. Also, because the conventional fixed gain PI controller are very sensitive to step change of command speed, parameter variations and load disturbance, the fuzzy logic controller is used to compensate a fixed gain PI controller. Therefore, a gain PI is fixed and the IPMSM is drived at another speed region. The effectiveness of the proposed the adaptive integral observer and the fuzzy logic controller are confirmed by experimental results.

• Journal of Power Electronics
• /
• v.18 no.6
• /
• pp.1708-1719
• /
• 2018

A complete current loop decoupling control strategy based on a sliding mode observer (SMO) is proposed to eliminate the influence of current dynamic coupling and back electromotive force (EMF) in the vector control of permanent magnet synchronous motors. With this strategy, current dynamic decoupling and back EMF compensation can be simultaneously achieved. Unlike conventional methods, the proposed strategy can avoid the disturbances caused by the parametric variations of motor systems and maintain the advantages of proportional integral (PI) controllers, which are robust and easy to operate. An improved SMO, which uses a special PI regulator other than a linear saturation function as the equivalent control law in the boundary layer of a sliding surface, is proposed to eliminate the estimated errors caused by the quasi-sliding mode and obtain a satisfactory decoupling performance. The stability and parameter robustness of the proposed strategy are also analyzed. Physical experimental results are presented to verify the validity of the method.

• Progress in Superconductivity and Cryogenics
• /
• v.25 no.4
• /
• pp.24-27
• /
• 2023

Until now, many research activities have been conducted to commercialize high-temperature superconducting (HTS) wires for electric applications. Most of all researchers have focused on enhancing the piece length, critical current density, mechanical strength, and throughput of HTS wires. Recently, HTS magnet for generating high magnetic field shows degraded performance due to the deformation of HTS wire by high electro-magnetic force. The deformation can be derived from widthwise thickness non-uniformity of HTS wire mainly caused by wet processes such as electro-polishing of metal substrate and electro-plating of copper. Gradient sputtering process is designed to improve the thickness uniformity of HTS wire along the width direction. Copper stabilizing layer is deposited on HTS wire covered with specially designed mask. In order to evaluate the thickness uniformity of HTS wire after gradient sputtering process, the thickness distribution across the width is measured by using the optical microscope. The results show that the gradient deposition process is an effective method for improving the thickness uniformity of HTS wire.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.24 no.6
• /
• pp.123-130
• /
• 2010

In general, a design method based on the equivalent magnetic circuit has been used for basic design of Interior Permanent Magnet Synchronous Motor(IPMSM). However, the equivalent magnetic circuit method has difficulty in considering the arrangement of PM. IPMSM has high degree of freedom for PM rotor design. In this paper, we proposed the multiobjective optimal design method considering the arrangement of PM for the double-layer PM rotor structure that minimizes the torque ripple as well as maximizes the torque of IPMSM. The design variables of double-layer PM rotor structure are obtained from the Response Surface Method. Torque and torque ripple were calculated by Finite Element Method.

• Proceedings of the KIEE Conference
• /
• 2002.07d
• /
• pp.2325-2327
• /
• 2002

포항 가속기연구소(PAL)에서는 포항방사광가속기(PLS)가 가동을 시작한 1994년 이후 현재까지 사용되어 온 기존의 제어 시스템을 새로운 환경인 EPICS(Experimental Physics and Industrial Control System) 시스템으로 개발하고 있다. EPICS 시스템의 구성은 IOC(Input/Ouput Controller) 와 OPI(Operator Interface)의 2-Layer로 구성되며 이는 MIU(Machine Interfaces Unit), SCC(Subsystem Computer Control System) 그리고 HMI(Human Machine Interface)로 이어지는 기존의 3-Layer 단계 중 SCC단계를 줄여 2-Layer로 구성된다. 이들 두 계층간의 통신은 Client(OPI)/Server(IOC) 구조의 Channel Access를 통해서 이루어진다. 개발중인 EPICS 시스템은 Open Architecture 구조로 IOC와 OPI 각 부분에서 개발시에 사용된 운영체제나 Hardware 를 사용하지 않고 다른 운영체제나 Hardware를 사용하더라도 하나의 공통부분 즉, Channel Access만 있으면 이를 통해 서로 다른 Subsystem IOC의 데이터를 Access할 수 있다. 전체 EPICS 제어시스템 중 저장링 운전의 핵심이 되는 BPM(Beam Position Monitoring) 및 MPS(Magnet Power Supply) 시스템은 IOC부분에 MVME5100(Target Machine) 보드와 vxWorks(Operating System)를 이용하고 OPI부분에는 SUN Workstation(Host Machine)와 Solaris(Operating System)을 사용하여 개발하고 있다. 본 논문에서는 IOC 및 OPI의 설치 절차와 설치 방법에 대해 기술하였다.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2003.10a
• /
• pp.226-229
• /
• 2003

Following the successful development of practical high temperature superconducting (HTS) wires, there has been renewed activity in the development of superconducting power equipments. HTS equipments must be operated in the coolant, such as liquid nitrogen (L$N_2$) or cooled by cooler, such as GM-cryocooler to maintain the temperature below critical temperature. In this paper, dielectric strength of some insulating materials, such as epoxy, teflon, and glass fiber reinforced plastic (GFRP) in L$N_2$was measured. Surface breakdown voltage of GFRP which is basic property in design of HTS solenoid coil was measured. Epoxy is a goof insulating material but it is fragile at cryogenic temperature. The multi-layer insulating method of current lead is suggested to compensate this fragile property. It consists of teflon tape layer and epoxy layer fixed with texture. Based on these measurements, the 6.6㎸ class HTS magnet for DC reactor type high-T$_{c}$ superconducting fault current limiter (SFCL) was successfully fabricated and tested.d.

• Progress in Superconductivity
• /
• v.2 no.2
• /
• pp.76-80
• /
• 2001

We have fabricated YBa$_2$Cu$_3$$O_{7-x}$ (YBCO) ramp-edge Josephson junctions by modifying ramp edges of the base electrodes without depositing any artificial barrier layer. YBa$_2$Cu$_3$O/7-x//SrTiO$_3$ (YBCO/STO) films were deposited on SrTiO$_3$(100) by on-axis KrF laser deposition. After patterning the bottom YBCO/STO layer, the ramp edge was cleaned by ion-beam and then reacted with deionized water under various conditions prior to the deposition of counter-electrode layers. The top YBCO/STO layer was deposited and patterned by photolithography and ion milling. We measured current-voltage (I-V) characteristics, magnetic field modulation of the critical current at 77 K. Some showed resistively shunted junction (RSJ)-type I-V characteristics, while others exhibited flux-flow behaviors, depending on the dipping time of the ramp edge in deionized water. Junctions fabricated using optimized conditions showed fairly uniform distribution of junction parameters such as I$_{c}$R$_{n}$ values, which were about 0.16 mV at 77 K with 1$\sigma$~ 24%. We made a dc SQUID with the same deionized water treated junctions, and it showed the sinusoidal modulation under applied magnetic field at 77 K. 77 K.

• Proceedings of the KIEE Conference
• /
• 2006.04b
• /
• pp.229-231
• /
• 2006

The paper presents a sensorless speed control of interior permanent magnet synchronous motors using an adaptive integral binary observer in view of composition with a main loop regulator and an auxiliary loop regulator. The binary observer has a property of the chattering alleviation in the constant boundary layer; however, the steady state estimation accuracy and robustness are dependent upon with width of the constant boundary. In order to improve the steady state performance of the binary observer, the binary observer is formed by adding extra integral dynamic to the switching hyperplane equation.

• Proceedings of the KIPE Conference
• /
• 1997.07a
• /
• pp.70-78
• /
• 1997

A DSP-based nonlinear speed control of a permanent magnet synchronous motor(PMSM) which is robust to unknown parameter variations and speed measurement error is presented. The model reference adaptive system(MRAS) based adaptation mechanisms for the estimation of slowly varying parameters are derived using the Lyapunov stability theory. For the disturbances or quickly varying parameters, a quasi-linearized and decoupled model including the influence of parameter variations and speed measurement error on the nonlinear speed control of the PMSM is derived. Based on this model, a boundary layer integral sliding mode controller to improve the robustness and performance of a PMSM drive is designed and compared with the conventional controller. To show the validity of the proposed control scheme, simulations and experimental works are carried out and compared with the conventional control scheme.