• Journal of Electrical Engineering and Technology
• /
• 제12권2호
• /
• pp.665-673
• /
• 2017

This paper proposes a field weakening control method for operating an induction motor with a variable DC input voltage condition. In the variable DC voltage condition such as a battery, the field weakening method are required for the maximum output power. The conventional field weakening control methods can be used for operating the induction motor over the rated speed in a constant DC-link voltage condition. However, the conventional methods for operating the motor with the variable DC voltage is not suitable for the maximum output power. To overcome this problem, this paper proposes the optimized field weakening control method to extend the operating range of the induction motor with a rated power in a limited thermal and a wide DC input voltage conditions. The optimized d-axis and q-axis current equations are derived according to the field weakening region I and II to extend the operating region. The experimental results are presented to verify the effectiveness of the proposed method.

• Asian-Australasian Journal of Animal Sciences
• /
• 제6권2호
• /
• pp.253-258
• /
• 1993

The study on the nutritive value and the potential use of two kinds (local vs. import) of sesame meal (SSM) in layer diets as substitute for soybean meal (SBM) at 25, 50, and 75% was carried out. Three hundred and thirty six layers were kept individually on a battery cage and fed isonitrogenous diets, 16% crude protein (CP), for 252 days. The local and the imported SSM contained on air dry basis 35.7 and 36.3% CP, 24.7 and 9.1% ether extract (EE), respectively. Their amino acid contents are all lower than those reported by NRC (1984). The local material contained remarkably lower lysine (0.44 vs. 0.94), methionine + cystine (1.06 vs. 1.75) and threonine (0.52 vs. 1.22) than the imported meal. Imported SSM could be substituted for SBM as high as 50% in layer ration without statistically adverse effect on egg production, feed intake, body weight gain, average egg weight and egg size, while local SSM was inferior to the control in all aspects. However, when production performance of the groups fed either kind of SSM was compared, no significant difference was found at the two lower substitution levels.

• 한국태양에너지학회 논문집
• /
• 제34권2호
• /
• pp.16-23
• /
• 2014

This paper presents a renewable energy configuration plan of Micro grid in Gapa Island. To analyze the characteristics of Micro grid, BESS (Battery Energy Storage System), PMSG (Permanent Magnet Synchronous Generator) and SCIG (Squirrel Cage Induction Generator) are first modelled. The PMSG and SCIG will operate with basis on the real power curve. when the total power demand is larger than the total power generation, the BESS will be operated and the SOC (State Of Charge) is reduced. If the value of SOC could drop down to limited value, the system may be broken because of the voltage drop of BESS. To solve this problem, a DG (Diesel Generator) is used to charge the BESS and keep the voltage value of BESS with in a allowance limit. This paper represents simulation result when PMSG, SCIG connected to the Micro grid installed in Gapa Island. The simulation is carry out by using PSCAD/EMTDC program with actual line constant and transformer parameter in Gapa Island.

• Journal of Power Electronics
• /
• 제7권2호
• /
• pp.97-108
• /
• 2007

This paper describes simple control structures for a vector controlled stand-alone induction generator (IG) for use under variable speeds. Different control principles, indirect vector control and deadbeat current control, are developed for a voltage source PWM converter and the three-phase variable speed squirrel-cage IG to regulate DC-link and generator voltages with a newly designed phase locked loop circuit. The required reactive power for the variable speed IG is supplied by means of a PWM converter and a capacitor bank to buildup the voltage of the IG without the need for a battery, to reduce the rating of the PWM converter while using only three sensors and to eliminate the harmonics generated by the PWM converter. These proposed schemes can be used efficiently for variable speed wind energy conversion systems. The measurements of the IG systems at various speeds and loads are given and show that these systems are capable of good AC and DC voltage regulation.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
• /
• pp.1339-1342
• /
• 2005

This paper presents a simple AC-DC power conditioner for a squirell-cage induction generator(IG) operating under variable shaft speeds. The necessary reactive power for the IG system is supplied by means of a capacitor bank and a voltage-source PWM converter. Using a capacitor bank to transfer the reactive power to the IG under the rated speed and no-load conditions starts the IG operation and reduces the PWM power converter size. A simple control compensating for changes in the electrical loads as well as the variation in speed was developed to regulate the voltages of the IG system by controlling the rotor flux through its reactive and active currents control implementation. This proposed power conditioning scheme can be used efficiently as a wind power generation system where the output voltage of the IG is maintained constant voltage despite the variable frequency and the DC bus voltage of the PWM converter can be used for either DC applications such as battery charging or AC power applications with 60/50 Hz by connecting a stand alone inverter. The experimental and simulated operating performance results of a 5 kW IG scheme at various speeds and leads are presented.

• 한국가금학회지
• /
• 제43권1호
• /
• pp.21-29
• /
• 2016

A total of 144 one-day-old male broilers (ROSS ${\times}$ Ross 308) ($42{\pm}0.1g$) were used in a completely randomized design and allotted to one of three dietary treatments to give 6 replicates per treatment (8 birds per cage). The three watery dietary treatments were 1) a corn-soybean meal-based relation [Negative control (NC); no antimicrobial compounds added] with tab water, 2) 8 ppm liquid-alpha-lipoic acid [Positive control (PC)] or 3) 100 ppm liquid-resveratrol. All dietary treatments were continuously provided as a liquid form. Birds were housed in a battery cage (n=48), and were offered liquid dietary treatments at all times. The ambient temperature was maintained at $32{\pm}1^{\circ}C$ for the first 3 weeks and decreased gradually to $28{\pm}1^{\circ}C$ by the end of the experiment (d 35) to induce moderate heat stress. One bird per pen (n=6) was euthanized via cervical dislocation at day 21 to obtain terminal ileum to measure villous height and crypt depth, while another bird per pen (n=6) was similarly euthanized at day 35 and used to harvest breast meat and drumsticks to evaluate meat quality traits. Birds fed liquid-resveratrol did not improve (P>0.05) body weight and average daily gain compared with those fed other dietary treatments from day 1 to day 35. Birds fed liquid-resveratrol had no effect (P>0.05) on villous height compared with birds were in other dietary treatments at day 21. Liquid-resveratrol had no effect (P>0.05) on thiobarbituric acid reactive substance (TBARS) in drumsticks compared with other dietary treatments at day 35. Furthermore, birds fed liquid-resveratrol had no effect (P>0.05) on DPPH radical scavenging activity both in breast meat and drumsticks compared with those fed other dietary treatments at day 35. Morphological changes of ileum were not observed by immunofluorescence, and the level of occludin protein from ileum extracts also did not differ among groups. Our results suggested that liquid form of antioxidant compounds used in the current study such as alpha-lipoic acid (8 ppm) or resveratrol (100 ppm) did not improve growth performance, meat quality traits and histology of terminal ileum compared with those fed negative control in broiler chickens under moderate heat stress for 35 days.

• 한국가금학회지
• /
• 제14권1호
• /
• pp.33-38
• /
• 1987

고-섬유질 곡류의 육계의 성장률, 도체조성 및 복강지방 함량에 미치는 영향을 조사하고자 갓 부화한 암평아리 240수를 공시하였다. 시험사료는 저-섬유질 곡류로서 옥수수와 수수를, 고-섬유질 곡류로서 호밀과 겉보리를 사용하였으며, 모든 사료는 에너지와 단백질 수준을 같게 하였다. 시험 설계는 4처리 5반복의 완전임의 배치법으로 하였으며, 반복당 12수를 철제 battery cage에 수용하였다. 통계적 유의성 검정은 5% 수준에서 실시하였고, 평균간의 비교는 신다준 검정법(Duncan, 1955)을 사용하였다. 육계의 성장률은 2주령 시에는 호밀 사료구가 6주령 시에는 수수와 호밀 사료구가 유의하게 불량하였으며, 사료 섭취량은 처리구별로 차이가 없었다. 사료효율은 3주령 시에는 유의성이 없었으나, 6주령 시에는 보리와 옥수수 사료구가 수수와 호밀 사료구에 비하여 유의하게 좋았다. 3주령된 육계의 내장 척출한 도체의 지방 함량은 호밀 사료구가 유의하게 낮았으며, 보리 사료구도 수수 사료구 보다는 낮았으나 옥수수구와는 유의한 차이가 없었다. 6주령된 육계의 내장 척출한 도체와 방혈ㆍ탈모만을 한 도체의 조성은 처리구별로 유의성이 없었다. 또한 복강지방 함량에 있어서도 곡류의 섬유질 함량에 따른 차이를 발견할 수 없었다.

• 한국가금학회지
• /
• 제23권3호
• /
• pp.129-134
• /
• 1996

본 연구는 사료내 마늘의 첨가가 육용계의 생산성 및 3-hydroxy-3-methylglutaryl coenzyme A(HMG-CoA) 환원효소에 미치는 영향을 구명하고자 실시하였다. 3주령의 육용계(Abor Acres) 50수를 처리구당 10수씩 마늘 0%, 0.3%, 0.6%, 1.0%를 첨가한 5개의 처리구에 배치하여 사료와 물은 자유채식시켰다. 사료섭취량, 중체량, 사료효율에 있어서 마늘 첨가에 의한 영향은 없었다. HMG-CoA 환원효소의 활성 및 간장과 혈청내 지질함량은 마늘 첨가에 의해 유의하게 감소되었다. 따라서 본 연구결과 마늘이 첨가된 사료를 급여한 육계의 혈액내 콜레스테롤의 감소는 HMG-CoA 환원효소 활성의 저하에 기인되는 것으로 사료된다.

• 농업과학연구
• /
• 제44권2호
• /
• pp.244-253
• /
• 2017

This study was conducted to investigate the growth performance indices among male commercial crossbred Korean native chickens from hatch to twelve weeks of age. A total of 312 one-day-old male birds were used for 6 groups of the commercial crossbred Korean native chicken within 1 paternal line and 6 maternal lines (1A, 2A, 3A, 4A, 5A, and 6A). The chickens were allocated to 24 battery cages to give 4 replicates per each crossbreed with 13 chickens per cage. Ad-libitum feeding was practiced throughout the experimental period and fresh water was available via nipple drinkers at all times. Body weight and feed intake were measured at two-week interval. Among six crossbreeds, the 2A group had the greatest (p < 0.05) body weight at week 8 and the greatest average daily weight gain in week 6 - 8. However, crossbreed 2A had the lowest viability (p < 0.05) at week 8 of all crossbreed groups as well as higher uniformity (p > 0.05) at week 2 than the others. No difference (p < 0.05) was found in any crossbreed Korean native chicken's growth performance indices including body weight, average daily gain, average daily feed intake, feed efficiency, uniformity, and viability after week 8. With this in mind, crossbreed 2A had greater bodyweight, average daily gain, average feed intake, and feed efficiency than the other Korean native chickens 84 days after hatch, although they had lower uniformity and viability than the others.

• Journal of Animal Science and Technology
• /
• 제62권6호
• /
• pp.840-853
• /
• 2020

The present study was conducted to investigate the effect of a multi-protease on production indicators of broiler chickens fed a crude protein and amino acid deficient-diets for 35 days immediately after hatch. A total of 448 one-day-old Ross 308 male broiler chicks were allocated in a completely randomized design into one of eight dietary treatments (positive control [PC], negative control [NC: minus 0.5% from PC, and minus 2% of lysine, methionine, threonine and methionine plus cysteine], extreme negative control [ENC: minus 1% from PC, minus 4% of lysine, methionine, threonine and methionine plus cysteine], and plus multi-protease 150 or 300 g per ton [e. g., PC-150]; PC, PC-150, NC, NC-150, NC-300, ENC, ENC-150, ENC-300) to give eight replicates with seven birds in a battery cage. Body weight, average daily gain, average daily feed intake, feed conversion ratio, and mortality were measured every week. Carcass traits, proximate analysis of breast meat, and ileum digestibility were analyzed on day 21 and 35. Feeding a multi-protease (i.e., more than 150 g/ton) for 35 days immediately after hatching improved feed efficiency and ileum digestibility (i.e., dry matter, crude protein, and energy) compared to their counterparts (i.e., diets without multi-protease: PC, NC, and ENC). In conclusion, our results indicated that broiler chickens fed nutrients deficient-diet (i.e., crude protein and amino acids) supplemented a multi-protease had an ability to compensate and (or) improve their growth performance commensurate with increased ileal digestibility for 35 days immediately after hatch.