This course introduces the basic concepts of power semiconductor devices, converters and choppers and their analysis. Phase control technique — Single phase Line commutated converters — Mid point and Bridge connections — Half controlled converters with Resistive, RL loads and RLE load— Derivation of average load voltage and current — Active and Reactive power inputs to the converters without and with Free wheeling Diode —Numerical problems.
Fully controlled converters, Mid point and Bridge connections with Resistive, RL loads and RLE load— Derivation of average load voltage and current — Line commutated inverters -Active and Reactive power inputs to the converters without and with Free wheeling Diode, Effect of source inductance — Derivation of load voltage and current — Numerical problems. Three phase converters — Three pulse and six pulse converters — Mid point and bridge connections average load voltage With R and RL loads — Effect of Source inductance—Dual converters both single phase and three phase — Waveforms —Numerical Problems.
McInnis, and K. He received his B. Tech, M. He has been working as a Asst. Professor from the past 4. His current interest is on improving the stability analysis, harmonic reduction using the FACT Devices. Samaba SivaNayak born on 9th August at Rajupalem.
Tech , M. He is presently working as a Asst. He had presented many paper in various conferences and published many papers in various publications. He is the key person for conducting many workshops and conferences. Manigandan, born on 16th November at Karikudi, Tamilnadu. He received his M.
Tech degree in the stream of Power electronics and Power system, in K. University, Vaddeswaram, Guntur Dist. He worked as a In charge H. R Polytechnic, Gudlavalleru. He worked as a Engineer in the Research Department in R. The structures of said insulating cylinder 10 and said transformer units 11 will be described in detail hereinafter referring to FIGS. In case of using a central tube 9 also as a primary conductor, hollow insulating cylinders 10a and 10b, vertically divided, surround the central tube 9.
Conductive layers 34 and 35 are disposed on the inner periphery of the insulating cylinder 10a and 10b along an imaginary longitudinal axis and are conductively connected to said central tube 9, respectively, so as to keep the oil gap between the central tube 9 and the insulating cylinders 10a, 10b at the same potential.
A transformer unit is fitted around an insulating cylinder, or , and comprises a magnetic iron core 37 made of molybdenum permalloy, etc. Said conductive layer 39 may be either embedded in the insulating body 40 as is shown in FIGS. A conductive layer 41 is formed in the surface portion of the insulating cylinder 10a or 10b corresponding to and facing each transformer unit 11 and is conductively connected to the conductive layer 39 of the corresponding transformer unit 11 by a conductor 42 to keep the gap between the insulating cylinder 10a or 10b and the transformer unit 11 at a uniform potential.
In the upper and lower end portions of each insulating cylinder, a plurality of conductive layers 43a and 44a are disposed to form a voltage dividing capacitor to uniformalize the electric field in the end portions of the insulating cylinder.
Conductive layers 45 electrostatically couple respective pairs of adjacent conductive layers 41 in a longitudinal direction, the detailed structure of which will be described with reference to FIG.
Said voltage dividing capacitor 46 comprises conductive layers 47a, 47b and disposed offset to each other between the conductive layers 41 corresponding to a pair of adjacent transformer units 11a and 11b. The number of the conductive layers forming said voltage dividing capacitor 46 may be arbitrarily selected. And the innermost conductive layer 47c of the capacitor 46 is conductively connected to the conductive layer By the above structure, the potential at the surface portion of each insulating cylinder can be determined and lines of electric force I between each pair of adjacent transformer units are distributed perpendicularly from the respective conductive layers of the capacitor 46 to the surface of the insulating cylinder 10a.
Thus, the potential distribution in the spacing between said transformer units can be uniformalized, rationally enabling a reduction in the size of this spacing.
The insulating cylinder on which respective transformer units are to be fitted may be composed of a single continuum. However, when the voltage in the thyristor circuit is relatively high, the insulating cylinder may be divided into two or more portions to facilitate the manufacture thereof, as is the case with the embodiment of FIG.
In the case of a divided insulating cylinder, consideration should be given not to allow the occurrence of a corona discharge at the jointed portions of the divided cylinder. In FIG. Further, the ends of respective conductive layers of the voltage dividing capacitor 43a at the end of the insulating cylinder 10a and those of the capacitor 44a at the end of the insulating cylinder are correspondingly offset to arrange for an equipotential surface between said ends of the two capacitors to perpendicularly cross the facing end surfaces of the two cylinders, thereby setting the electric lines of force so that they extend along and within the gap g between the two cylinders.
Thus, the insulation in the junction portion is strengthened. Here, the innermost electrodes of the voltage dividing capacitors 43a and 44a are maintained at an equal potential through the conductive layers 3d, 35 and the central tube 9, and the outermost electrodes are conductively connected to each other by a connection wire The gap g between said insulating cylinders 10a and 10b is continuously open at the inner periphery to the oil gap 36 to introduce insulating oil and is hermetically sealed at the outer periphery with a packing In the above embodiments, one secondary winding is wound in each transformer unit.
However, a plurality of secondary windings may be wound on each unit as is shown in FIG. In the figure, secondary windings 38a, 38b, 38c and 38d are separately disposed on a magnetic iron core 37 and respectively connected to lead-out terminals The transformer unit 11 is coupled to an insulating cylinder 10b through coupling means 51a to 51d.
It will be apparent that the above structure enables a reduction in the number of transformer units and hence the overall size of the pulse transformer is also reduced. Further, as is shown in FIG. In this structure, connection to the serial thyristors is alternately made from the right half portion and the left half portion to uniformalize the electric field in the transformer.
Advances in Power Electronics and Instrumentation Engineering. Alternative Energy in Power Electronics. Power Electronics. Digital Power Electronics and Applications. Introduction to Modern Power Electronics. Power Electronic Modules: Design and Manufacture. Power Electronics: Advanced Conversion Technologies. Power Electronics and Motor Drives.
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