• The Korean Journal of Pharmacology
• /
• v.12 no.2 s.20
• /
• pp.51-59
• /
• 1976

Methylene bis (3, 4, 6-trichlorophenoxy acetic acid) 'MTPA' has been developed for the purpose of treatment of clonorchiasis. It has been rpeorted that, in patients treated with MTPA, the flukes in the liver were killed, elevated serum bilirubin returned to normal and the patients´ general condition was improved. However it took $1{\sim}4 $ weeks to obtain sufficient therapeutic effects. In rabbits, excretion of bilirubin in the bile was increased by the MTPA, and this action was enhanced by a combination of deoxycholic acid with MTPA. This study was designed as a part of a series to increase the therapeutic effect of MTPA, by observing the relation of the blood level of MTPA with the excretion of MTPA in the bile, and the excretion of MTPA with bilirubin excretion in the bile caused by the injection of MTPA alone or in combination with deoxycholic acid. $^{14}C-labeled$ MTPA alone or with deoxycholic acid were injected into the ear veins of rabbits. The amout of bile, MTPA and bilirubin in the bile and the blood level of MTPA were measured. The results obtained were as follows: 1. The amount of excreted bile was decreased gradually as the time elapsed in both groups, that is groups injected with MTPA alone and with deoxycholic acid, without any significant difference between either group. 2. The largest amount of MTPA excretion in the early stage of the MTPA excretion in both groups, but deoxycholic acid caused an increase in blood level of MTPA whereas biliary excretion of MTPA decreased, especially in the early stage after drug injection. 3. The significant increment of bilirubin excretion began within an hour and it reached peak level in $2{\sim}2\frac{1}{2}$ hours after drug injection in both groups, but the amount of excreted bilirubin was larger in the combined group. The above results suggest that deoxycholic acid interferes with the biliary excretion of MTPA, and that there is no close relation between the increased excretion of MTPA and bilirubin excretion. But there is a close relation between blood level or tissue concentration of MTPA and bilirubin excretion. Concerning the influence of deoxycholic acid on the therapeutic effect of MTPA, deoxycholic acid would enhance the effect of MTPA, if the parasites take the drug from the blood, but diminish its effectiveness if they take the drug from the bile.

• The Korean Journal of Pharmacology
• /
• v.9 no.1
• /
• pp.39-46
• /
• 1973

It has been reported previously that 2,2-methylene bis(3,4,6-trichlorophenoxy acetic acid) (MTPA) is effective treating for clonorchiasis and less toxic to the hosts. In this studies the absorption, distribution and excretion of MTPA were observed. For this purpose $^{14}C-MTPA$ was synthesised from bis(2-hydroxy-3,5,6-trichlorophenoxyl) methan $^{14}C$ and administerd to the normal rabbit in a single dose of 10mg/kg IV or 20 mg/kg P.O. or to the Clonorchis infected rabbit in dose of 20 mg/kg/day for 6 days. Radioactivity in blood, tissue, bile, urine, feces and tissue of the fluke was measured after the drug was given. The concentration of MTPA in these samples were calcurated from the radioactivity. The result obtained as followes. 1. The increase in concentration of MTPA in blood and urine after oral administration of MTPA was so slow that the absorption of MTPA from the gastrointestinal tract appears very slow. 2. It is presumed that the excretion of MTPA also is slow because the reduction of MTPA concentration in blood after IV injection was very slow. 3. Large amount of MTPA was excreted from the bile. 4. During repeat dose of 20mg/kg/day for 6 days the concentration of MTPA in blood and tissue gradually increased. 5. The highest concentration of MTPA in the kidney and liver, heart, lung, spleen and muscle in decreasing order and the lowest concentration in the brain was noted. 6. During daily dose of 20 mg/kg of MTPA for 6 days of administration the concentration of MTPA gradually increased in urine and feces and the concentration of MTPA in feces was higher than of in urine. It appeares that MTPA take place enterophepatic circulation. 7. It is assumed that accumulation in large amount of MTPA in the liver and tissue of clonorchis, excretion of large amount from the bile is a favorable property of MTPA as a chemotherapeutic agent for clonorchiasis.

• Journal of IKEEE
• /
• v.26 no.4
• /
• pp.653-658
• /
• 2022

This paper presents a Maximum Torque per Ampere (MTPA) control algorithm for an interior permanent magnet synchronous motor (IPMSM) drive considering the permanent magnet (PM) flux linkage variations due to PM temperature variation. PM flux linkage are estimated in real time via a Gopinath style stator flux linkage observer and a torque error correction factor is calculated from the estimated PM flux linkage. A 2-dimensional (2D) MTPA look-up table (LUT) is developed to achieve the MTPA trajectory reflecting PM flux linkage variation for compensating torque error occurred by parameter variation. The proposed IPMSM control algorithm is verified through simulations.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.15 no.2
• /
• pp.142-149
• /
• 2010

Interior Permanent Magnet Synchronous Motor(IPMSM) have gained an increasing popularity in recent years for a variety of industrial applications, because of their high power density, high efficiency and possibility of flux weakening operation. Because the efficiency of IPMSM is one of the important performance characteristic, the Maximum Torque Per Ampere(MTPA) operating method has been indispensible. In theory, MTPA operating point can be calculated using the exact values of the machine parameters. However, the values of the IPMSM parameters are known to vary widely according to the operating condition. Therefore, to operate the IPMSM in the MTPA operating point, the machine parameters should be estimated in real-time. In this paper, the new MTPA operating method based on the signal injection is presented. By injecting the high frequency current signal, the MTPA operating criteria can be calculated by measuring the input power to IPMSM. The proposed method can find the MTPA operating point with simple signal processing regardless of the parameter variation.

• Proceedings of the KIPE Conference
• /
• 2009.11a
• /
• pp.102-104
• /
• 2009

매입형 영구자석 동기 전동기는 높은 효율과 빠른 동특성, 넓은 정출력 운전 영역 등의 장점 때문에 다양한 산업 분야에서 각광을 받고 있다. 특히 최대 효율 운전을 위해서 매입형 영구자석 동기기의 단위전류당 최대 토크(Maximum Torque Per Ampere, MTPA) 운전 방법에 대한 많은 연구들이 수행되어져 왔다. 이론적인 MTPA 운전점은 전동기의 제 정수에 의해 결정되는데, 매입형 영구자석 동기 전동기는 온도와 운전 영역에 따라 전동기제 정수의 변화가 극심하여 정확한 MTPA 운전을 하기 위해서는 전동기의 전 운전 영역에 대한 전동기 제정수를 미리 알고 있어야 한다. 실시간으로 전동기 제 정수를 추정하여 MTPA 운전점을 알아내는 방법도 제안되었으나 대부분 복잡한 비선형 방법이 적용되고 있다. 본 논문에서는 신호 주입 개념을 도입한 새로운 MTPA 운전 방법을 제안한다. 전류에 높은 주파수의 신호를 주입하여 그 주입된 신호에 의한 반응을 확인함으로 MTPA 운전점을 판별하게 된다. 이 방법은 전동기 제 정수 변동에 강인하며, 간단한 신호처리 과정만으로 MTPA 운전을 할 수 있다.

• Proceedings of the KIPE Conference
• /
• 2018.07a
• /
• pp.426-427
• /
• 2018

본 논문에서는 철손을 고려한 SPMSM(Surface mounted Permanent Magnet Synchronous Motor)의 모델로부터 출력 토크를 향상시킬 수 있도록 하는 개선된 MTPA(Maximum Torque Per Ampere) 제어 기법을 제안하였다. d축 전류를 0으로 사용하는 SPMSM의 기존 MTPA 제어 방식보다 철손을 고려한 MTPA 전류로 운전하는 제안된 방식이 더 큰 출력 토크를 얻을 수 있음을 800W PMSM에 대한 시뮬레이션을 통해 확인하였다.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.23 no.4
• /
• pp.240-246
• /
• 2018

In this paper, a sensorless V/f control based on maximum torque per ampere (MTPA) operation for PMSMs is proposed. Given that the MTPA operation is not considered in the conventional sensorless V/f control, efficient PMSM drives cannot be achieved. Therefore, this paper proposes an improved technique based on the d-axis current control to enable the MTPA operation in the V/f control for PMSMs. A stabilization technique is also proposed to improve the dynamic characteristics and stability against load variation. The effectiveness of the proposed technique is verified by conducting experiments with a 250 W SPMSM for driving a blower.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.21 no.1
• /
• pp.65-71
• /
• 2016

This study investigates a high-accuracy alternate QD model to estimate the characteristics of induction motor under light loads. To demonstrate the usefulness of the alternate QD model, a maximum torque per amp (MTPA) control based on the alternate model is shown to outperform MTPA control based on the standard QD model. The experimental study conducted in this work exhibits that the MTPA control based on the alternate QD model tracks torque commands between 20 Nm and 30 Nm with 5% error, whereas the MTPA control based on the standard QD model generates torques lower by over 23% compared with the aforementioned torque commands. This result indicates that the alternate QD model is a highly accurate model for induction motors under light loads.

• Proceedings of the KIPE Conference
• /
• 2017.11a
• /
• pp.189-190
• /
• 2017

본 논문에서는 PMSM에서 단위 전류당 최대 토크를 발생시키는 MTPA(Maximum Torque Per Ampere)제어에 기반한 센서리스 V/f 운전 기법을 제안한다. 기존의 센서리스 V/f 운전에서는 MTPA 제어가 고려되지 않아 구동 효율이 감소하는데 본 논문에서는 d축 전류를 기반으로 비례적분기 제어기를 사용하여 개선하였다. 또한 부하 변동에 대한 우수한 동특성과 안정성을 갖도록 하였다. 250W 블로워용 PMSM(Permanent Magnet Synchronous Motor)에 대한 실험을 통해 그 효용성을 확인하였다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.11
• /
• pp.5128-5134
• /
• 2011

This paper investigates the dq current trajectory for maximum torque per ampere(MTPA) operation of an interior PM synchronous motor for HEV(Hybrid Electric Vehicle). Based on the dq current trajectory for the MTPA operation derived from the motor parameters, the change of the MTPA operating point for the variation of the motor parameters including the magnet flux and the dq inductances is considered. The dq current trajectory for MTPA operation is verified through the experiment.