• Structural Engineering and Mechanics
• /
• 제29권5호
• /
• pp.581-597
• /
• 2008

In this paper, the double displacement coupled statics and dynamics of the electromechanical integrated electrostatic harmonic drive are developed. The linearization of the nonlinear dynamic equations is completed. Based on natural frequency and mode function, the double displacement coupled forced response of the drive system to voltage excitation are obtained. Changes of the forced response along with the system parameters are investigated. The voltage excitation can cause the radial and tangent coupled forced responses of the flexible ring. The flexible ring radius, ring thickness and clearance between the ring and stator have obvious influences on the double displacement coupled forced responses.

• Structural Engineering and Mechanics
• /
• 제60권6호
• /
• pp.1079-1092
• /
• 2016

In this paper, an electromechanical integrated harmonic piezodrive system is proposed. The operating principle of the drive system is introduced. The equation of the relationship between the displacements of the flexible ring and the rotating angle of the rotor is deduced. Using the equation, the displacements of the flexible ring for the drive system and their changes along with the system parameters are investigated. The results show that the displacements of the flexible ring changes periodically along with the rotation of the vibrator; there are abrupt changes in the displacements of the flexible ring at some points where there are abrupt changes in the number of the mesh teeth pair; the length of the flexible ring, the excitation voltage, and the speed ratio have obvious effects on the displacements of the flexible ring. The results are useful for the design of the drive system. ;

• 한국정보통신학회논문지
• /
• 제15권2호
• /
• pp.425-431
• /
• 2011

전기추진선박에서 해결해야 할 중요한 문제점의 하나는 전력변환시에 발생되는 전류 및 전압파형에 포함된 고조파 성분에 의한 손실과 토크리플이다. 이를 제거하기 위해서 많은 방식들이 연구되고 있으며 본 논문에서는 상천이 변압기를 갖는 다중펄스 드라이브를 사용하여 정류된 직류파형을 개선함으로서 전류 및 전압파형에 포함되는 고조파 성분을 감소시키는 방식을 사용하였다. 또한, 그 유효성을 입증하기 위해서 6펄스 및 12펄스 드라이브를 각각 전력변환장치로 사용하였으며 현재 대형 선박에서 사용중인 6000[kW]의 유도전동기를 추진전동기로 채택하여 시뮬레이션을 행하였다. 다중펄스 드라이브에 의한 고조파 저감은 발전기 출력측의 전류파형과 추진전동기 입력측의 전압 파형에 포함된 총고조파 왜형율을 평가하였으며 또한, 고조파에 의한 전동기측의 영향은 추진전동기의 토크리플을 측정하여 비교 분석하였다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제48권3호
• /
• pp.104-109
• /
• 1999

In order to design and predict the performance of the harmonic side drive motor, it is necessary to analyze the torque generated by the structure. In this paper, an analytical model is proposed for design. Conformal mapping is used to model the capacitance and torque of the motor as a function of the rotor angular position with two-dimensional approximation. Then the result of conformal mapping analysis is verified with F.E.M result.

• 대한기계학회논문집
• /
• 제14권3호
• /
• pp.526-533
• /
• 1990

본 연구에서는 단일 캠 구동기구의 안정성 해석을 위한 효율적인 방법이 제시 되고, 수치실험을 통하여 검증되었다. 우선 단일 캠 구동기구를 묘사하는 비선형 방 정식이 유도되고, 동안정성에 관여하는 변수들이 무차원화되어 도입된다. 유도된 방 정식은 캠 축의 입력각에 대하여 선형화되고, 선형화된 방정식에 조화균형법(harmonic balance method)을 적용하여 동안정성 해석을 수행하였다.

• 조명전기설비학회논문지
• /
• 제25권4호
• /
• pp.124-134
• /
• 2011

A new dead time compensation scheme that can exactly estimate the dead time and inverter nonlinearity under parameter variations is proposed for a PWM inverter-fed PMSM drive. The proposed scheme uses the fact that the sixth harmonic component in total disturbance estimated under the presence of various uncertainties is mainly caused by the dead time and inverter nonlinearity. The total disturbance due to the parameter variations as well as the dead time and inverter nonlinearity is estimated by the adaptive scheme. The sixth harmonic component is extracted from this total disturbance through harmonic analysis. The obtained sixth harmonic is processed by the PI controller to estimate the disturbance caused by the dead time and inverter nonlinearity in the stationary reference frame. The effectiveness of the proposed scheme is verified. Without requiring an additional hardware, the proposed scheme can effectively compensate the dead time and inverter nonlinearity even under the parameter variations.

• 대한전기학회논문지
• /
• 제34권9호
• /
• pp.368-375
• /
• 1985

This paper describes the OPTIMAL PWM strategy to reduce harmonic losses for a variaboe-speed drive of an induction motor. This OPTIMAL theory is the strategy which can reduce motor losses by defining harmonic losses as a performance index and achieving it's minimization. This PWM strategy is compared with the conventional NATURAL PWM technique by a numerical method, and verified the validity of numerical method by a result of implementing in a practical 1 Hp-3 Phase induction motor drive system. Also, we could achieve a maximum efficiency to drive an induction motor by selecting appropriately one alternative between OPTIMAL and NATURAL PWM techniques, and employing it in a full driving range.

• 전기학회논문지P
• /
• 제67권1호
• /
• pp.1-8
• /
• 2018

ACL and DCL are have been conventionally used for reducing harmonic current on the input side of an ACMD. The current distortion ratio ITHD using ACL and DCL is only 35% to 85%, therefore to satisfy the IEEE Std. 519 requirements, the line filters has been focused as an alternative means. Those are installed between the AC power supply and the input of the ACMD, and must meet the IEEE Std. 519, be economical and be compact. To contribute to the widespread of using these line filters, we discussed concerning its topologies, simulation results, prototype test results as well as the cost evaluations. It included not only the proposed (NHHF) new hybrid harmonic filters which have both merits of simplicity and economic but also the past (BBHF) broadband harmonic filters and (HHF) hybrid harmonic filters.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 1989년도 제10회 학술강연회초록집
• /
• pp.78-85
• /
• 1989

Conventional theory of gear mechanism can not be applied to analyze the harmonic drive due to specific movement of the tooth. Therefore, external tooth profile can't be manufactured by conventional exclusive tools which have pressure angle of 20$\circ$C. This paper deals with an analysis of kinematics and strength analysis of tooth. Then a theoretical new tooth profile of the flexspline and method of manufacture of external tooth profile are presented.

• Tribology and Lubricants
• /
• 제5권2호
• /
• pp.107-112
• /
• 1989

This paper deals with strength analysis of tooth and method of manufacture of external tooth profile in harmonic drive. From the calculation of load imposed on the contact teeth, moximum contact stress is investigated to design the addendum modification coefficient. New tooth profile of the external gear is generated according to the law of gearing, assuming that internal gear has involute tooth profile. External tooth profile can't be manufactured by conventional exclusive tools which have pressure angle of 20$\circ$. The method to design cutter tooth profile is presented.