變壓器의 等價回路 定數決定法

左宗根 제주대학교 1980 논문집 Vol.12 No.-

The T-type equivalent circuit constants of transformers with regard to magnetic saturation, are studied. And these constants are determined by measuring both prinary and secondary resistance, and also by the no-load test (at 60% and 100% of rated voltage) and the rated frequency short-circuit test (at 50%, 100% and 200% of rated current). By using these constants, the characteristics are calculated accurately, and the calculated values and measured values are compared.

變壓器와 結合된 單相브리지 整流回路의 脈動電流計算法

左宗根 제주대학교 1983 논문집 Vol.16 No.-

變壓器와 結合된 單相브리지 整流回路의 等價回路에 의한 直流脈動電流計算에 대한 硏究結果 主要內容은 다음과 같다. 1) 對象負荷와 要求精度에 따라 本 方法을 利用하여 脈動電流를 簡便하게 計算할 수 있다. 2) 逆起電力負荷에서는 誤差가 X?에 거의 無關하고 E??/E?가 클수록 크다. 3) 抵抗負荷에서는 誤差가 R?가 클수록 작아지고 X?가 클수록 커진다. 4) 抵抗-逆起電力負荷에서는 誤差가 E??/E?의 값에 따라 -에서 +로 變하고 誤差가 ±10%以內인 E??/E?의 範圍는 X?가 클수록 좁아진다. Using equivalent circuit, a calculating method of ripple current of single rectifier combined with transformer was studied. The validity of the equivalent circuit method developed in this study was examined by comparing its results with those obtained from Irie's method. In order to develop the model, some circuit conditions were considered, and the results obtained are as follows. 1) Employing this method, ripple current could be easily calculated according to the object and required accuracy. 2) In emf load, the error is almost not affected by X? while greater E??/E? makes greater error. 3) In resistance load, error decreases with the increasing R? while increases with increment of X? of ±10% is becoming narrower with the increase ofX?value.

變壓器 過渡勵磁電流計算에 미치는 等價回路定數의 影響

左宗根 제주대학교 1985 논문집 Vol.21 No.-

實測資料만에 의하여 變壓器 過度勵磁電流計算을 위한 T型等價回路를 構成하고 回路定數 변화에 대한 影響을 檢討하여 回路定數의 決定方法은 물론 電流計算方法도 提是하였다. 檢討한 決果 1. 回路定數를 決定기 위한 試驗은 1次捲線低抗測定, 無負荷試驗, 短試驗 및 Hysteresis 特性測定이 필요하며 2. r₁의 값은 1次低抗測定 決果値를 25。C로 換算하고 3. r??을 考廬하여 計算하여야 함을 알았다. T-type equivalent circuit, composed by test data, is used to calculate the transient magnetizing currents. Using this circuit, and method of determining circuit parameters considered the effect of the parameters variation as well as the method of computing inrush currents. The results obtained are as follows; 1) To determine the circuit parameters, primary winding-resistance measurement, open circuit test, short circuit test and hysteresis characteristic measurements are required. 2) The value of r₁, measured by primary winding-resistance measurement, should be converted into the resistance at 25。C. 3) The core loss resistance(r??) is necessary to compute the magnetizing inductance.

風力 驅動 自己勵磁 誘導發電機의 解析 : 節点法과 루우프法의 比較 Comparison of Nodal and Loop Method

左宗根 濟州大學校工科大學産業技術硏究所 1995 尖端技術硏究所論文集 Vol.6 No.-

Two methods for the steady state analysis of wind driven self-excited induction generators are investigated in this paper. In this analysis, the T-type equivalent circuit neglected the core loss is used to predict the steady state performance under the resistance load. Computed results for the loop impedance and the nodal admittance method show very good agreement between the two. To maintain a constant terminal voltage and frequency, a simple method for determining the parameters speed, terminal capacitance, and exciting reactance is also introduced.

風力 驅動 自己勵磁 誘導發電機의 端子 커패시턴스 豫測

左宗根 제주대학교 1994 논문집 Vol.39 No.-

풍력으로 구동되는 자기여자 유도발전기가 정격속도로 운전할 때 여자회로의 자기포화곡선을 구간 선형화하여 거의 모든 영역에서 자기여자작용을 일으킬 수 있는 커패시턴스의 값을 구하여 분석하였다. 또한 정격 단자전압을 유지하기 위한 커패시턴스의 값을 구하기 위한 간결한 방법도 제시하였다. 일정 부하, 정격속도 운전시에 대한 분석결과는 다음과 같다. 1) 공극전압이 커질수록, 여자리액턴스가 작아질수록 커패시턴스가 커진다. 2) 주파수가 낮아질때, 높은 단자전압이 필요할 때 큰 커패시턴스가 필요하다. 3) 부하의 종류와 크기에 따라 필요커패시턴스가 다르다. 일정 공극전압, 정격속도, 부하변화시에 정격전압을 유지할때는 부하임피이던스가 증가함에 따라 커패시던스가 작아지고, 주파수도 떨어진다. The loop analysis to predict the terminal capacitance value required for self excitation of an isolated self-excited induction generator supplying a balanced R-L load is investigated. Two nonlinear equations have to be solved to obtain this capacitance value. In this paper a straightforward method is introduced to predict the capacitance requirement for most all of saturated region under constant speed operation. A simple method is also introduced for computing the capactance required for maintaining the preset terminal voltage under the variable load.

過渡勵磁電流 計算을 위한 變壓器 磁化曲線의 表現

左宗根 제주대학교 1984 논문집 Vol.19 No.-

實驗結果로부터 얻어진 變壓器 磁化曲線의 解析的 表現方法에 대하여 硏究하였다. 磁化曲線의 曲線部分은 몇 개의 指數函數를 直線部分은 1次函數를 써서 表現하였고 이 結果를 ??,Mactadyen의 方法과 比較하였다. 그리고 實測한 過渡勵磁電流와 위의 方法들에 의하여 計算한 電流를 比較하여 本 方法이 過渡電流 計算에 適合함을 보였다. A new method is suggested determing an analytical expression for the saturation characteristic of tranformer from the experimental results. To express this characteristic, some exponential functions and a linear function are used. The accuracy of this technique is verfied by comparing with other methods.

整流回路를 考慮한 變壓器 等價回路

左宗根 제주대학교 1981 논문집 Vol.13 No.-

整流回路를 考慮한 單相變壓器 等價回路를 1) 電流의 重複角과 2) 重複角에 의한 電流成分의 影響도 考慮하여 3) 交流側에서 特性을 算定할 수 있도록 構成하였다. 이 等價回路에서 特性을 算定하여 實驗値와 比較한 結果 잘 一致하고 있으므로 整流回路를 가진 變壓器의 特性解析에 有用한 資料가 될 것이다. A steady-state wquivalent circuit of transformer using bridge rectifier in the secondary circuit was investigated. In order to determine this equivalent circuit, the current overlap angle u and the effects of current componets based on u were considered. From this equivalent circuit, the operation characteristics of this system were described and calculated. Some experimental results were compared with calculated value in graphical form.

풍력 구동 자기여자 유도발전기의 해석 : 절점법과 루우프의 비교

좌종근 濟州大學校 産業技術硏究所 1995 산업기술연구소논문집 Vol.6 No.-

Two methods for the steady state analysis of wind driven self-excited induction generators are investigated in this paper. In this analysis, the T-type equivalent circuit neglected the core loss is used to predict the steady state performance under the resistance load. Computed results for the loop impedance and the nodal admittance method show very good agreement between the two. To maintain a constant terminal voltage and frequency, a simple method for determining the parameters speed, terminal capacitance, and exciting reactance is also introduced.

風力驅動 單相 誘導發電機의 數値解析

左宗根 濟州大學校工科大學産業技術硏究所 1997 尖端技術硏究所論文集 Vol.8 No.1

Newton Raphson algorithm using difference method for a wind driven self-excited single-phase induction generator is proposed, when the capacitor is connected to the auxiliary winding and the load to the main winding. This method requires only simple numeric calculations. comparing with other reported methods which contain monotonous and complicated algebraic manipulation. As the computed results, we find that the three difference methods can be applied to Newton Raphson algorithm. Also, the initial guess values and the step size are affected in the number of iterations. Furthermore, the central difference method is better than the forward and the backward difference method in the number of iterations.

풍력구동 자기여자 유도발전기의 해석 : Newton Raphson법과 정할법의 비교

좌종근 濟州大學校 産業技術硏究所 1996 산업기술연구소논문집 Vol.7 No.1

The Newton Raphson method and the secant method for the steady state analysis of a wind driven self-excited induction generator are presented and compared in this paper. The nodal admittance method which involves simple algebraic calculations is used for this analysis. Very good agreement between the two numerical methods has been obtained on several load conditions, but it is found that the secant method is better than the Newton Raphson method in the number of iteration and the length of program.