• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.3
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• pp.300-305
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• 2013

The torque was calculated with inductance and iron loss. Because the linkage flux can change the inductance, and q-axis current can change the iron loss. Therefore, precise estimation of torque can achieve with the inductance and iron loss detail calculations. So, in this paper, the d, q-axis inductance was verified through CVCT(Current Vector Control Test) and DCT(Direct Current Test). Also in the iron loss calculation, the prediction of all areas of current magnitude, phase angle and speed was very difficult. And LUT(Look-Up Table) was spent time and resource largely. Therefore, iron loss mathematization was proposed according to current magnitude, phase angle and speed. Also, characteristics of IPMSM were comprised of analyzed and experimental values.

• Journal of Power Electronics
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• v.2 no.2
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• pp.88-94
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• 2002

The demand for protection of power electronic application has during the last couple of vears increased regarding the high-power IGBT modules. Even with an active protection, a high power IGBT still has a risk of exhibiting a violent rupture in the case of a fault if IGBT Fuses do not protect it. By introducing fuses into the circuit this will increase the circuit inductance and slight inductance over-voltage during the turn-off of the diode and the IGBT. It is therefore vital when using fuses that the added inductance is kept at a minimum. This paper discuss three issues regarding the IGBT Fuse protection of adding inductance of existing High-speed and new Typower Fuse protection. First, the problem of adding inductance of exiting High-speed and new Typower Fuse DC-link circuit is treated, second a short discussion of protection of the IGBT module is done, and finally, the impect of the high frwquency loading on the currying capability of the fuses is presented.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1074-1076
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• 2005

Magnetic Inductance Tomography System은 비투자율이 공기보다 큰 대상물체를 외부에서 자기장을 인가하여 자기장의 변화를 자기센서로 측정하여 대상물체의 형상, 위치, 비투자율을 측정하고 판단하는 시스템이다. Magnetic Inductance Tomog-raphy System은 비투자율이 공기보다 큰 대상물체를 외부에서 자기장을 인가하여 자기장의 변화를 자기센서로 측정하여 대상물체의 형상, 위치, 비투자율을 측정하고 판단하는 시스템이다. Magnetic Inductance To-mography System은 대상물체의 위치, 모양, 크기에 따라 자기장의 변화가 달라게 된다. 대상물체를 실시간으로 측정하기 위하여 Magnetic Inductance To-mography System을 자기장 발생부와 신호변환부, 모니터링 부로 구분하여 구축하였다. 또한 대상물체를 위치를 이동시키거나 크기를 변경하여 대상물체의 신호를 해석, 측정하였다.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.230-235
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• 2017

When the characteristics of a linear induction motor (LIM) are analyzed using finite element analysis (FEA), it is desirable to set the voltage source as an input. If the voltage source is set as an input in FEA, the leakage inductance and primary resistance of the equivalent circuit must be entered by direct calculation, and the magnetizing inductance and secondary reaction effects are directly considered in FEA. Exact calculation is necessary because the primary winding resistance and leakage inductance directly entered will have a significant effect on the LIM output. Therefore, in this study, we accurately calculated the primary leakage inductance and analyzed the resulting LIM characteristics. We calculated the leakage inductance using an analytical equation and FEA, and we confirmed the accuracy by comparing the results with the value experimentally calculated using a manufactured model. We also analyzed the instrument performance and thrust of the LIM as a function of the difference in the leakage inductance. Finally, we present the conclusions on the precise analysis based on the calculation of the leakage inductance.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.6
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• pp.254-261
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• 2003

This study investigates magnetic circuit design of the Single-phase Line-start Permanent Magnet Synchronous Motor (LSPM) to develop the characteristics in steady state. In this paper, the saliency ratio, that is the ratio of q-axial inductance to d-axial inductance, and the inductance difference between q-axial inductance and d-axial inductance are increased. Design factor is selected permanent magnet position and rotor diameter. The analysis method of the synchronous motor on d-/q- axis coordinates is used for the positive component and the equivalent circuit of the induction motor is applied for the negative component analysis. Back-emf and d-q- axial inductance is analyzed by using 2 dimensional Finite Element Method (FEM). Characteristic analysis results with variation of design factor are reflected magnetic circuit design of LSPM. The characteristics of design model are compared with the characteristic of initial model.

• Journal of Power Electronics
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• v.15 no.6
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• pp.1567-1576
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• 2015

Offline inductance identification of a permanent magnet synchronous motor (PMSM) is essential for the design of the closed-loop controller and position observer in sensorless vector controlled drives. On the base of the offline inductance identification method combining direct current (DC) offset and high frequency (HF) voltage injection which is fulfilled at standstill, this paper investigates the inverter nonlinearity effects on the inductance identification while considering harmonics in the induced HF current. The negative effects on d-q axis inductance identifications using HF signal injection are analyzed after self-learning of the inverter nonlinearity characteristics. Then, both the voltage error and the harmonic current can be described. In addition, different cases of voltage error distribution with different injection conditions are classified. The effects of inverter nonlinearities on the offline inductance identification using HF injection are validated on a 2.2 kW interior PMSM drive.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.752-760
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• 2018

In this paper, interior permanent magnet synchronous motor (IPMSM) design for sensorless drive, considering magnetic neutral point shift according to magnetic saturation, has been proposed. Sensorless control was divided into a method based on inductance and a method based on back induced voltage. Because induced voltage is very small at zero or low speed, error in rotor initial position estimation may occur. Using the ratio of saliency addresses this problem. When using high-frequency injections at low speed, the rotor's initial position is estimated at the smallest portion of the inductance. IPMSM has the minimum inductance at the d-axis. However, if magnetic saturation leads to magnetic neutral point variation, following the load current change, there is a change in the minimum point of inductance. In this case, it can lead to failure of initial rotor position estimation. As a result, it is essential that the blocking design has an inductance minimum point shift. As such, in this study, an IPMSM design method, by blocking magnetic neutral point change, has been proposed. After determining the inductance profile based on the finite element analysis (FEA), the results of proposed method were verified.

• Journal of Power Electronics
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• v.14 no.5
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• pp.908-917
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• 2014

For the purpose of designing an intrinsic safety Flyback converter with minimal output voltage ripple based on a specified output current, this paper first classified the energy transmission modes of the system into three sorts, namely, the Complete Inductor Supply Mode-CCM (CISM-CCM), the Incomplete Inductor Supply Mode-CCM (IISM-CCM) and the Incomplete Inductor Supply Mode-DCM (IISM-DCM). Then, the critical secondary self-inductance assorting the three modes are deduced and expressions of the output voltage ripples (OVR) are presented. For a Flyback converter with constant loads and switching frequency, it is shown that the output voltage ripple in the CISM-CCM is the smallest and that it has no relationship with the secondary self-inductance. Otherwise, the OVR of the other two modes are bigger than the previously mentioned one. It is concluded that the critical inductance between the CISM-CCM and the IISM-CCM is the minimal secondary self-inductance to ensure the smallest output voltage ripple. At last, a design method to guarantee the minimum OVR within the scales of the input voltage and load are analyzed, and the minimum secondary self-inductance is proposed to minimize the OVR. Simulations and experiments are given to verify the results.

• Journal of Magnetics
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• v.16 no.1
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• pp.74-76
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• 2011

Interior permanent-magnet synchronous motors (IPMSMs) produce both magnetic and reluctance torques. The reluctance torque is due to the difference between the d- and q-axis inductances based on the geometric rotor structure. The steady-state performance analysis and precise control of the IPMSMs greatly depend on the accurate determination of the parameters. The three essential parameters of the IPMSMs are the armature flux linkage of the permanent magnet, the d-axis inductance, and the q-axis inductance. In the basic design step of an IPMSM, the inductance parameters are very important for determining the motor characteristics, such as the input voltage, torque, and efficiency. Thus, it is very important to accurately estimate the values of the motor inductances. The inductance parameters of IPMSMs have nonlinear characteristics along the magnet size because the iron core is saturated by the magnet and armature reaction fluxes. In this study, the inductance parameters were calculated using both the magnetic-equivalent-circuit method and the finite-element method (FEM). Then the calculated parameters were compensated by the saturation coefficient function, which was also calculated via the magnetic-equivalent-circuit method and FEM.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1996.04a
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• pp.95-99
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• 1996

In this paper, we proposed a method to measure the gap between the magnetic pole and the levitated object applying the inductance characteristic which vary according to gap. We made a driving circuit which supply the control input PWM(Pulse Width Modulation) signal and the carrier PWM signal to estimate the gap. Because the inductance is a function of gap, and the current of the carrier signal is a function of the inductance. We investigated the validity of the proposed method through the experimental results.