논문 : 노외기계시스템공학 ; 농업용 트랙터의 주요 농작업 소요동력 분석

김용주 ( Y. J. Kim ),정선옥 ( S. O. Chung ),박승제 ( S. J. Park ),최창현 ( C. H. Choi ) 한국농업기계학회 2011 바이오시스템공학 Vol.36 No.2

The purpose of this study was to analyze power requirement of an agricultural tractor by major field operations. First a survey was conducted to obtain annual usage ratio of agricultural tractor by field operation. Plowing, rotary tillage, and loader operations were selected as major field operations of agricultural tractor. Second, a power measurement system was constructed with strain-gauge sensors to measure torque of four driving axles and a PTO axle, speed sensors to measure rotational speed of the driving axles and an engine shaft, pressure sensors to measure pressure of hydraulic pumps, an I/O interface to acquire the sensor signals, and an embedded system to calculate power requirement. Third, the major field operations were experimented under fields with different soil conditions following planned operation paths. Power requirement was analyzed during the total operation period consisted of actual operation period (plowing, rotary tillage, and loader operations) and period before and after the actual operation (3-point hitch operating, forward and reverse driving, braking, and steering). Power requirement of tractor major components such as driving axle part, PTO part, main hydraulic part, and auxiliary hydraulic part were measured and calculated to determine usage ratio of agricultural tractor power. Results of averaged power requirement for actual field operation and total operation were 23.1 and 17.5 kW, 24.6 and 19.1 kW, and 14.9 and 8.9 kW, respectively, for plowing, rotary tillage, and loader operations. The results showed that rotary tillage required the greatest power among the operations. Averaged power requirement of driving axles, PTO axle, main hydraulic part, and auxiliary part during the actual field operation were 8.1, 7.8, 3.4, and 1.5 kW, respectively, and the total requirement power was about 70% (20.8 kW) of the rated power. Averaged power requirement of driving axles, PTO axle, main hydraulic, and auxiliary hydraulic for the total operation period were 6.5, 6.0, 2.1, 0.9 kW, respectively, and total requirement power was about 52% (15.5 kW) of the rated power. Driving axles required the greatest amount of power among the components.

Theoretical Analysis of Power Requirement of a Four-Row Tractor-Mounted Chinese Cabbage Collector

Swe Khine Myat,ISLAM MD NAFIUL,Chowdhury Milon,ALI MOHAMMOD,Wing Sandah,전현종,이상희,정선옥,김대건 한국농업기계학회 2021 바이오시스템공학 Vol.46 No.2

Purpose Analysis of power requirement is the key issue to ensure the optimal design. The objectives of the study were to investigate theoretically the tractor hydraulic power and draft power requirement of a tractor-mounted Chinese cabbage collector system and to suggest design guidelines. Methods The major components of the Chinese cabbage collector under development were a belt type conveyor, a hydraulic motor, and three hydraulic cylinders. Hydraulic motor power, cylinder hydraulic power, and draft power for various speeds under unloaded and loaded conditions were calculated using theoretical equations. Different tractor configurations (44~74 kW), soil types (sand, silt, and clay), and hydraulic fluid capacity (1~5m3/hr) were considered to determine the tractor hydraulic power and engine power requirement. Results The power requirement of the hydraulic motor for the unloaded and loaded conditions was 1.14 kW and 1.24 kW, respectively, under the 120-rpm conveyer speed. Hydraulic power of 2 ×10−3 kW was required to fold or unfold the collecting conveyor. The maximum required draft power levels were 0.67, 0.81, 0.94, and 1.21 kW for the hard, firm, tilted, and soft soil conditions, respectively. Based on the results, the total maximum power requirement was calculated as 15.14 kW, of which 7.25 kW is for the hydraulic power (48%) and 7.89 kW for the draft power (52%), respectively. Conclusion The analysis of power requirements presented in this research can help estimate the tractor hydraulic power and draft power requirement to run a tractor-mounted Chinese cabbage collector efficiently.

논문 : 노외기계시스템공학 ; 베일러 작업 시 트랙터 소요동력 분석

김용주 ( Yong Joo Kim ),이대현 ( Dae Hyun Lee ),정선옥 ( Sun Ok Chung ),박승제 ( Seung Jae Park ),최창현 ( Chang Hyun Choi ) 한국농업기계학회 2011 바이오시스템공학 Vol.36 No.4

Purpose of this study was to analyze power requirement of an agricultural tractor for baler operation. First, a power measurement system was developed and installed in a 75 kW agricultural tractor. Strain-gages with a telemetry system were used to measure torques of transmission and PTO input shafts. An engine tachometer was used to measure rotational speed of transmission and PTO input shafts. The measurement system also included pressure sensors to measure pressure of hydraulic pumps, an I/O interface to acquire the sensor signals, and an embedded system to determine power requirements. Second, field experiments were conducted at two PTO speed levels, and proportion of utilization ratio of rated engine power and power consumption of major parts (transmission input shaft, PTO input shaft, main hydraulic pump, and auxiliary hydraulic pump) were analyzed. Results of usage proportion of engine power for PTO speed level 1 and 2 were 4.1 and 2.2%, 31.5 and 16.3%, 49.6 and 59.7%, 14.4 and 20.8%, and 0.4 and 1.0%, respectively, for ratio of measured engine power to rated engine power of less than 25%, 25 ~ 50%, 50 ~ 75%, 75 ~ 100%, and greater than 100%. The results showed that the usage proportion increased in the range with the ratio of power requirement to rated engine power of over than 50% when the PTO gear was shifted from P1 to P2. Averaged engine power requirement for baling operation, tying and discharging operation, and total operation were 43.3, 37.3, and 42.0 kW and 49.0, 37.0, and 47.4 kW, respectively, for PTO speed level 1 and 2. Paired t-test showed significant difference in power consumption of engine, transmission input shaft, and PTO input shaft for different PTO speed levels. Therefore, the power consumption of engine for baler operation increased when the PTO gear was shifted from P1 to P2. It was indicated that the power requirement of tractor was affected by the PTO rotational speed for baler operation.

Optimal Power Control Strategy for Wind Farm with Energy Storage System

Cong-Long Nguyen,Hong-Hee Lee 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.2

The use of energy storage systems (ESSs) has become a feasible solution to solve the wind power intermittency issue. However, the use of ESSs increases the system cost significantly. In this paper, an optimal power flow control scheme to minimize the ESS capacity is proposed by using the zero-phase delay low-pass filter which can eliminate the phase delay between the dispatch power and the wind power. In addition, the filter time constant is optimized at the beginning of each dispatching interval to ensure the fluctuation mitigation requirement imposed by the grid code with a minimal ESS capacity. And also, a short-term power dispatch control algorithm is developed suitable for the proposed power dispatch based on the zero-phase delay low-pass filter with the predetermined ESS capacity. In order to verify the effectiveness of the proposed power management approach, case studies are carried out by using a 3-MW wind turbine with real wind speed data measured on Jeju Island.

주요 농작업에 따른 78kW급 농업용 트랙터의 소요 동력 분석

김완수,김연수,김택진,박성운,최용,최일수,김영근,김용주 대한기계학회 2019 大韓機械學會論文集A Vol.43 No.12

The aim of this study is to analyze the power requirement of a 78 kW agricultural tractor for the optimal design of a power transmission system. Moldboard plow tillage, disc plow tillage, rotary tillage, baler operation and loader operation are selected as major agricultural operations. The power measurement system is constructed for the driving axle, PTO axle, main hydraulic pump and auxiliary hydraulic pump. The total power requirement for the moldboard plow tillage, disc plow tillage, rotary tillage, baler operation and loader operation are 53.69, 37.50, 65.61, 36.84 and 17.55 kW, respectively. The rotary tillage consumed about 84 % of the engine rated power, with the highest required power compared to other agricultural operations. The power requirement of the driving axle, PTO axle, main hydraulic pump and auxiliary hydraulic pump are 13.6, 31.5, 2.01 and 1.84 kW, respectively. The sum of the power requirements is 48.9 kW, which is 63 % of the engine rated power. 본 연구는 트랙터의 동력전달시스템 최적 설계를 위한 기초연구로써 78kW급 농업용 트랙터의 소요 동력을 분석하기 위하여 수행되었다. 트랙터 소요 동력 계측시스템은 주요 동력 소모원인 차축, 동력 취출 장치, 주 유압펌프, 보조 유압펌프에 대하여 구축하였으며, 필드시험은 주요 농작업기 5종에 대하여 수행하였다. 몰드보드 플라우, 디스크 플라우, 로타리, 베일러, 로더 작업 시 총 소요 동력은 각각 53.69, 37.50, 65.61, 36.84, 17.55kW로 나타났다. 본 연구에서 수행한 농작업 중 로타리 경운 작업에서 엔진 정격출력의 약 84%의 동력 소모로 가장 높은 소요 동력을 나타냈으며, 로타리 경운 작업 외 주요 농작업별 평균 소요 동력은 엔진 정격출력의 70% 미만 수준으로 나타났다. 주요 동력 소모원별 소요 동력은 차축, PTO 축, 주 유압펌프, 보조 유압펌프에서 각각 13.6, 31.5, 2.01, 1.84kW로 나타났으며, 주요 동력 소모원의 소요 합은 48.9kW로, 정격 출력의 63%를 사용한 것으로 나타났다.

에너지 절감형 트랙터 로타리날 개발 (Ⅳ) : 로타리 커버 흙 부착 방지장치의 개발 Development of Device of Preventing soil Adherence for Rotary

김찬수,김기대,권병철 한밭대학교 생산기반기술연구소 2003 생산기반기술연구소 논문집 Vol.3 No.1

This study was development of soil adherent preventing device for farming rotary. Because, in case that soil adhere to the upper/lower cover of farming rotary, the required power of tillage operation is increase. And was development the measuring device of the required power of tillage for the measurement of required power in performance testing. The result of the study are summaried as follows: (1) The high density polyethylene plate was attached to the upper/lower cover of farming rotary for the prevention of the increase of required power. (2) The measuring device of required power was developed for performance test of the developed soil adhere preventing device. (3) The result of performance test showed that the required power of tillage operation was reduced to 12.2%.

Optimal Power Control Strategy for Wind Farm with Energy Storage System

Nguyen, Cong-Long,Lee, Hong-Hee The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.2

The use of energy storage systems (ESSs) has become a feasible solution to solve the wind power intermittency issue. However, the use of ESSs increases the system cost significantly. In this paper, an optimal power flow control scheme to minimize the ESS capacity is proposed by using the zero-phase delay low-pass filter which can eliminate the phase delay between the dispatch power and the wind power. In addition, the filter time constant is optimized at the beginning of each dispatching interval to ensure the fluctuation mitigation requirement imposed by the grid code with a minimal ESS capacity. And also, a short-term power dispatch control algorithm is developed suitable for the proposed power dispatch based on the zero-phase delay low-pass filter with the predetermined ESS capacity. In order to verify the effectiveness of the proposed power management approach, case studies are carried out by using a 3-MW wind turbine with real wind speed data measured on Jeju Island.

힘의 경쟁시대 동아시아 역학구도 전망과 한국의 대응방향: 힘의 경쟁시대 힘의 요건을 중심으로

백병선 세종연구소 2018 국가전략 Vol.24 No.2

After Trump seizes power, the uncertainty and instability of security environment increase and all four neighboring powers are strongly pushing for national-centered foreign strategies. The dynamics of East Asia can be said to be the competition between the U.S. and the China forces with the forces they are forming. Following this power competition, The East Asia's dynamics are likely to remain in the hegemony of the U.S. under the G2 era, the establishment of the G2 era under new type of major power relationship which China claims, the East Asia G2+2 or the G4 Including Japan and Russia in East Asia. The main reason for this change in the dynamics of East Asia can be found in the change of ability, will and intervention. In the three dynamic types after Trump seize power, South Korea should strengthen its power. Specifically, South Korea's strength is to speak properly on major security issues. This means not only deterrent power against North Korea’s threats, but also that it should be equipped with restraining influence against threats from neighboring countries. 트럼프 대통령 집권 이후 안보환경의 불확실성과 불안정성이 더해 가고 있으며, 주변 4강 모두 강력한 힘을 기반으로 자국 중심의 대외전략을 강력하게 추진하고 있다. 동아시아 지역의 역학구도는 미ㆍ중간 힘의 경쟁과 이들이 형성하고 있는 세력 간의 경쟁이라고 할 수 있으며, 이러한 힘의 경쟁에 따라 동아시아의 역학구도는 G2시대 형성 하에 미국의 패권 유지, 중국이 주장하는 신형대국관계 하 G2시대 형성과 아울러 일본 및 러시아가 포함된 동아시아 G2+2 또는 G4 시대로 변화할 가능성도 배제할 수 없는 상황이다. 이러한 동아시아 역학구도 변화의 주요 원인은 능력, 의지, 개입 등의 변화라고 할 수 있으며, 트럼프 집권 이후 예상되는 3가지 유형의 역학구도에서 한국이 힘을 갖추는 것은 시대적인 요구사항이라고 할 수 있다. 구체적으로 한국의 힘은 주요 안보현안에 대해서 제대로 된 목소리를 내는 것이며, 이는 곧 북한의 위협에 대한 억제력뿐만 아니라 주변국의 위협에 대비할 수 있는 견제력을 갖추어야 한다는 것을 의미하는 것이다.

Ancillary Service Requirement Assessment Indices for the Load Frequency Control in a Restructured Power System with Redox Flow Batteries

Chandrasekar, K.,Paramasivam, B.,Chidambaram, I.A. The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.6

This paper proposes various design procedures for computing Power System Ancillary Service Requirement Assessment Indices (PSASRAI) for a Two-Area Thermal Reheat Interconnected Power System (TATRIPS) in a restructured environment. In an interconnected power system, a sudden load perturbation in any area causes the deviation of frequencies of all the areas and also in the tie-line powers. This has to be corrected to ensure the generation and distribution of electric power companies to ensure good quality. A simple Proportional and Integral (PI) controllers have wide usages in controlling the Load Frequency Control (LFC) problems. So the design of the PI controller gains for the restructured power system are obtained using Bacterial Foraging Optimization (BFO) algorithm. From the simulation results, the PSASRAI are calculated based on the settling time and peak over shoot concept of control input deviations of each area for different possible transactions. These Indices are useful for system operator to prepare the power system restoration plans. Moreover, the LFC loop coordinated with Redox Flow Batteries (RFB) has greatly improved the dynamic response and it reduces the control input requirements and to ensure improved PSASRAI, thereby improving the system reliability.

Ancillary Service Requirement Assessment Indices for the Load Frequency Control in a Restructured Power System with Redox Flow Batteries

K. Chandrasekar,B. Paramasivam,I.A. Chidambaram 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.6

This paper proposes various design procedures for computing Power System Ancillary Service Requirement Assessment Indices (PSASRAI) for a Two-Area Thermal Reheat Interconnected Power System (TATRIPS) in a restructured environment. In an interconnected power system, a sudden load perturbation in any area causes the deviation of frequencies of all the areas and also in the tie-line powers. This has to be corrected to ensure the generation and distribution of electric power companies to ensure good quality. A simple Proportional and Integral (PI) controllers have wide usages in controlling the Load Frequency Control (LFC) problems. So the design of the PI controller gains for the restructured power system are obtained using Bacterial Foraging Optimization (BFO) algorithm. From the simulation results, the PSASRAI are calculated based on the settling time and peak over shoot concept of control input deviations of each area for different possible transactions. These Indices are useful for system operator to prepare the power system restoration plans. Moreover, the LFC loop coordinated with Redox Flow Batteries (RFB) has greatly improved the dynamic response and it reduces the control input requirements and to ensure improved PSASRAI, thereby improving the system reliability.