Study on Influence of Rotor Temperature Variation on the Performance of Maximum Torque Per Amp Control Strategy

권춘기,Kwon, Chun-Ki The Korea Academia-Industrial cooperation Society 2009 한국산학기술학회논문지 Vol.10 No.11

회전자 온도 변화는 유도 전동기 제어기 설계에 있어서 중요한 쟁점이다. 문헌에서, 수많은 연구들이 회전자 온도 변화를 고려하지 않는다면, 그에 기인한 심각한 성능 저하를 언급해왔다. 하지만, 이러한 연구들은 추종 성능 관점에서 주로 Field-oriented 제어기에 초점을 두고 있으며, 단위 전류당 최대 토크 제어기와 같이 최적 제어의 경우에서의 성능에 미치는 회전자 온도 변화의 영향에 대한 연구는 전무하다. 본 연구는 회전자 온도가 시간에 따라 변화함에 따라, 단위 전류당 최대 토크 제어기의 성능에 어떻게 영향을 미치는지를 조사한다. 이를 위해, 두 가지 방법으로 단위 전류당 최대 토크 제어기의 목적이 성취되는 지를 점검한다. 즉, 요구되는 토크를 발생시키면서 동시에 최소 가능한 고정자 전류를 필요로 하는 것이다. 실험실 실험결과는 추종 성능과 단위 전류당 최대 토크 조건이 회전자 온도가 변화함에 따라 심각한 영향을 받으며, 결과적으로 단위 전류당 최대 토크 제어기의 성능저하를 초래함을 보여준다. Rotor temperature variation is a significant issue in the design of induction motor controls. In the literature, numerous studies have mentioned significant performance degradation due to rotor temperature variation unless it is taken into account. However, those studies have mainly focused on field-oriented control in terms of tracking performance. There was little research about the influence of rotor temperature variation on performance particularly in the case of optimal controls such as maximum torque per amp (MTPA) control strategy. This work investigates how to affect the performance of maximum torque per amp (MTPA) control strategy as rotor temperature varies in time. To this end, investigation was carried out in two ways to see whether the objective of MTPA control strategy is achieved regardless of rotor temperature variation. It is to produce a desired torque with the minimum possible stator current at the same time. Laboratory experiment shows that tracking performance and maximum torque per amp condition is significantly affected by rotor temperature variation as rotor temperature varies, thus ending up with performance degradation of MTPA control.

An On-line Rotor Resistance Estimator for Induction Machine Drives

권춘기 전력전자학회 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.3

Rotor resistance variation due to changing rotor temperature is a significant issue in the design of induction motor controls. In this work, a new on-line rotor resistance estimator is proposed based on an alternate qd induction machine model which provides better mathematical representation of an induction machine than the classical qd model (which uses constant parameters). This is because the former simultaneously includes leakage saturation, magnetizing path saturation, and distributed circuit effects in the rotor conductors. The comparisons via computer simulation studies show the ability of the proposed estimator to accurately track rotor resistance variation. For the experimental studies, due to the difficulty in measuring the actual rotor resistance, comparison of the controller performance using the proposed estimator, the classical qd model based estimator, and no estimator is made.

Alternate QD 유도전동기 모델에서의 고정자 자기 인덕턴스의 온도 변화에 관한 연구

권춘기 순천향대학교 부설 산업기술연구소 2013 순천향 산업기술연구소논문집 Vol.19 No.2

유도전동기의 우수한 성능은 유도전동기의 모델을 기반으로 설계된 제어기에 의해 좌우되므로, 모델 파라미터의 정 확한 추정 없이는 기대할 수 없다. 따라서, 우수한 성능 확보를 위해, 유도전동기의 모델과 이에 상응하는 모델 파라 미터 추정 절차에 관한 연구가 꾸준히 진행되어 왔다. 이러한 노력으로, 유도전동기의 동특성을 표현할 수 있는 정확 한 모델과 이에 상응하는 파라미터의 추정절차가 잘 정립되어, 유도전동기의 고성능 운전이 가능하게 되었다. 하지만, 유도전동기 모델의 파라미터들은 유도전동기의 운전 시에 제공되는 전류에 의해 발생하는 온도 상승으로 인 해 추정된 모델 파라미터와 유도전동기의 실제 파라미터의 불일치가 발생한다. 이러한 온도 상승에 따른 파라미터 불 일치를 해소하기 위한 방안으로 모델 파라미터를 추정하는 연구가 많이 진행되어 왔으나, 대부분의 연구들이 유도전 동기의 회전자 저항에 국한되어 왔다. 따라서, 본 연구에서는 유도전동기의 특성을 잘 나타내는 우수한 모델인 Alternate QD Model을 활용하여, 온도 변화에 따른 고정자 자기 인덕턴스의 변화를 고찰하여, 온도 변화에도 정확한 모델을 추정할 수 있도록 하는데 주안점을 두 었다.

Study on an Adaptive Maximum Torque Per Amp Control Strategy for Induction Motor Drives

권춘기 대한전기학회 2013 Journal of Electrical Engineering & Technology Vol.8 No.1

Maximum Torque Per Amp (MTPA) control for induction motor drives seeks to achieve a desired torque with the minimum possible stator current. This is favorable in terms of inverter operation and nearly optimal in terms of motor efficiency. However, rotor resistance variation can cause significant performance degradation. This work demonstrates that existing MTPA controls perform sub-optimally as temperature varies. An adaptive MTPA control strategy is proposed that always achieves optimal performance without exhibiting hunting phenomenon regardless of rotor temperature. The proposed control is experimentally shown to accurately achieve the desired torque.

Study on Optimal Condition of Adaptive Maximum Torque Per Amp Controlled Induction Motor Drives

권춘기 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.1

Adaptive Maximum Torque Per Amp (Adaptive MTPA) control for induction motor drives seeks to achieve a desired torque with the minimum possible stator current regardless of operating points. This is favorable in terms of inverter operation and nearly optimal in terms of motor efficiency. However, the Adaptive MTPA control was validated only from the viewpoint of tracking a desired torque and was not shown that the desired torque is achieved with minimum possible stator current. This work experimentally demonstrates that optimal condition for Adaptive Maximum Torque Per Amp Control Strategy is achieved regardless of rotor resistance variation

Korean Finger Number Gesture Recognition Based on CNN Using Surface Electromyography Signals

권춘기,Jong-Jun Park 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.1

This study proposes a recognition strategy for Korean fi nger number gestures based on convolutional neural network (CNN) using surface electromyography (sEMG) signals. A few studies have reported Chinese fi nger number gesture recognition using sEMG signals. However, fi nger number gestures vary across diff erent regions, prompting the need to investigate fi nger number gesture recognition specifi c to Koreans. To this end, six Korean fi nger number gestures ranging from zero to fi ve were selected and recognized by CNN using sEMG signals acquired from four pairs of electrodes on forearm muscles. In this study, we investigated the feasibility of CNN in fi nger number gesture recognition using sEMG time series data. The experimental results show that CNN achieved a 100% recognition rate over six Korean fi nger number gestures using sEMG time-series data. A comparative analysis of diff erent studies indicates that the proposed approach may be at least comparable to the existing studies selected in this work. It is therefore a more convenient and promising platform for recognition of fi nger number gestures.

Study on Performance of Adaptive Maximum Torque Per Amp Control in Induction Motor Drives at Light Load Operation

권춘기,공용해,김동식 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.1

Efficient operation of induction motor at light loads has been getting wide attention recently because the operating of induction motor at light loads occupies big portion of its operating regions in many applications such as environment friendly vehicle. As one of approaches to improve efficiency, Adaptive Maximum Torque Per Amp (Adaptive MTPA) control for induction motor drives has been proposed to achieve a desired torque with the minimum possible stator current. However, the Adaptive MTPA control was validated only at heavy load where, in general, control scheme tends to perform better than at light loads since the error in measurement of sensors is lower and signal to noise is better. Thus, although the performance of a control scheme is good at rated operating point, its performance at light load is somewhat in doubt in practice. This has led to considerable interest in efficiency of Adaptive MTPA control at light loads. This work experimentally demonstrates performance of Adaptive MTPA control at light loads regardless of rotor resistance variation, thus showing its good performance over all operating conditions.

단위전류당최대토크 제어기의 성능 비교를 통한 경부하에서 대안모델의 유도전동기 동특성 예측에 관한 연구

권춘기(Chun-Ki Kwon),김동식(Dong-Sik Kim) 전력전자학회 2016 전력전자학회 논문지 Vol.21 No.1

기준모델 추종 자기 구성 제어기

권춘기(Choon-Ki Kwon),배상욱(Sang-Wook Bae),박태홍(Tae-Hong Park),박귀태(Gwi- Tae Park) 대한전기학회 1993 대한전기학회 학술대회 논문집 Vol.1993 No.11

유도전동기의 고정자와 회전자의 스큐 형상에 관한 연구

권춘기(Chun-Ki Kwon),공용해(Yong-Hae Kong) 한국정보기술학회 2021 한국정보기술학회논문지 Vol.19 No.11

The skewing in stator or rotor has been very useful method to reduce torque ripples caused by alignment of stator and rotor slots along the stack. Unlike the existing conventional skewing method, we proposed skewing in both stator and rotor at the same time. Maxwell motor 3D simulation results confirmed that torque ripples in the proposed method improves torque ripples to 11.4% compared to 18.4% of torque ripples in the existing method. The proposed skew method might be very useful in electric battle submarines where reduction of slot harmonics in propulsion drives is one of important factors to avoid detection by the enemy, thus improving vessel survivability.