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Admittance

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and core losses. These shunt components can be referenced to the primary or secondary side. For simplified transformer analysis, admittance from shunt elements can be neglected. When shunt components have non-negligible effects on system operation, the shunt admittance must be considered. In the diagram below, all shunt admittances are referred to the primary side. The real and imaginary components of the shunt admittance, conductance and susceptance, are represented by
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In the context of electrical modeling of transformers and transmission lines, shunt components that provide paths of least resistance in certain models are generally specified in terms of their admittance. Each side of most transformer models contains shunt components which model magnetizing current
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Transmission lines can span hundreds of kilometers, over which the line's capacitance can affect voltage levels. For short length transmission line analysis, which applies to lines shorter than 80 kilometres (50 mi), this capacitance can be ignored and shunt components are not necessary in the
716: 707: 472: 548: 888:{\displaystyle {\begin{aligned}\left|Y\right|&={\sqrt {G^{2}+B^{2}}}={\frac {1}{\sqrt {R^{2}+X^{2}}}}\\\angle Y&=\arctan \left({\frac {B}{G}}\right)=\arctan \left(-{\frac {X}{R}}\right)\,,\end{aligned}}} 721: 553: 352: 148: 1009: 930:
Note that (as shown above) the signs of reactances become reversed in the admittance domain; i.e. capacitive susceptance is positive and inductive susceptance is negative.
159:). Likewise, admittance is not only a measure of the ease with which a steady current can flow, but also the dynamic effects of the material's susceptance to polarization: 155:
is a measure of the opposition of a circuit to the flow of a steady current, while impedance takes into account not only the resistance but also dynamic effects (known as
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Ushida, Jun; Tokushima, Masatoshi; Shirane, Masayuki; Gomyo, Akiko; Yamada, Hirohito (2003). "Immittance matching for multidimensional open-system photonic crystals".
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model. Lines from 80 to about 250 kilometres (50 to about 155 mi), generally considered to be in the medium-line category, contain a shunt admittance governed by
1227: 702:{\displaystyle {\begin{aligned}G&=\mathrm {Re} (Y)={\frac {R}{R^{2}+X^{2}}}\,,\\B&=\mathrm {Im} (Y)=-{\frac {X}{R^{2}+X^{2}}}\,.\end{aligned}}} 1041: 1179: 54: 956: 81:
to represent the magnitude of admittance, but it quickly became the conventional symbol for admittance itself through the publications of
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is a measure of how easily a circuit or device will allow a current to flow. It is defined as the
1117: 1091: 467:{\displaystyle Y=Z^{-1}={\frac {1}{R+jX}}=\left({\frac {1}{R^{2}+X^{2}}}\right)\left(R-jX\right)} 1040: 1175: 1139: 1109: 485: 273: 70: 1105: 923: 909: 239: 101: 62: 1216: 1121: 17: 955: 919: 477: 226: 1113: 260:
Parts of this article or section rely on the reader's knowledge of the complex
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Admittance, just like impedance, is a complex number, made up of a
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This article is about electrical engineering. For other uses, see
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The dynamic effects of the material's susceptance relate to the
66: 58: 69:, and its symbol is ℧ (an upside-down uppercase omega Ω). 711:
The magnitude and phase of the admittance are given by:
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in the alphabet, the conventional symbol for impedance.
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Shunt admittance in electrical power systems modeling
719: 551: 500: 355: 292: 167: 123: 1003: 887: 701: 525: 466: 317: 192: 142: 1156:Grainger, John J.; Stevenson, William D. (1994). 1172:Power System Analysis and Design, Fifth Edition 1138:, p. 88, Johns Hopkins University Press, 1992 1197:"Equivalent- π Representation of a Long Line" 8: 1030:is the length of the transmission line; and 286:, is composed of real and imaginary parts, 1184:Transmission Lines: Steady-State Operation 65:(symbol S); the older, synonymous unit is 1095: 997: 968: 877: 862: 831: 795: 782: 772: 761: 748: 742: 720: 718: 691: 682: 669: 659: 636: 618: 609: 596: 586: 566: 552: 550: 519: 499: 429: 416: 406: 378: 366: 354: 311: 291: 186: 166: 130: 122: 1024:is the shunt admittance per unit length; 1174:, Cengage Learning, Connecticut, 2012, 1074: 254:Conversion from impedance to admittance 143:{\displaystyle Y\equiv {\frac {1}{Z}}} 1228:Electrical resistance and conductance 1170:J. Glover, M. Sarma, and T. Overbye, 7: 1004:{\displaystyle Y=yl=j\omega Cl\,,} 808: 640: 637: 570: 567: 25: 1136:Steinmetz: Engineer and Socialist 77:in December 1887. Heaviside used 1036:is the capacitance of the line. 104:, is defined as the inverse of 27:Ease of electrical current flow 1018:is the total shunt admittance; 650: 644: 580: 574: 1: 248:universal dielectric response 89:simply because it is next to 543:(susceptance) are given by: 209:is the admittance (siemens); 85:. Heaviside probably chose 32:Admittance (disambiguation) 1244: 1114:10.1103/PhysRevB.68.155115 61:unit of admittance is the 55:conductance and resistance 29: 1059:SI electromagnetism units 526:{\displaystyle Y=G+jB\,,} 318:{\displaystyle Z=R+jX\,,} 276:representation of signals 193:{\displaystyle Y=G+jB\,,} 83:Charles Proteus Steinmetz 1160:. New York: McGraw-Hill. 272:and on knowledge of the 1054:Nodal admittance matrix 488:part (the susceptance, 480:part (the conductance, 1044: 1005: 959: 889: 703: 527: 468: 319: 194: 144: 39:electrical engineering 1158:Power System Analysis 1043: 1006: 958: 890: 704: 528: 469: 320: 195: 145: 18:Electrical admittance 967: 717: 549: 498: 353: 290: 165: 121: 1223:Physical quantities 1106:2003PhRvB..68o5115U 922:, also measured in 53:, analogous to how 1045: 1001: 960: 885: 883: 699: 697: 539:(conductance) and 523: 464: 315: 264:representation of 190: 140: 1180:978-1-111-42577-7 1134:Ronald R. Kline, 1084:Physical Review B 870: 839: 802: 801: 767: 689: 616: 436: 397: 138: 57:are defined. The 16:(Redirected from 1235: 1208: 1207: 1205: 1203: 1195:Ghosh, Arindam. 1192: 1186: 1168: 1162: 1161: 1153: 1147: 1132: 1126: 1125: 1099: 1097:cond-mat/0306260 1079: 1035: 1029: 1023: 1017: 1010: 1008: 1007: 1002: 952:, respectively. 951: 947: 917: 903: 894: 892: 891: 886: 884: 876: 872: 871: 863: 844: 840: 832: 803: 800: 799: 787: 786: 777: 773: 768: 766: 765: 753: 752: 743: 734: 708: 706: 705: 700: 698: 690: 688: 687: 686: 674: 673: 660: 643: 617: 615: 614: 613: 601: 600: 587: 573: 542: 538: 532: 530: 529: 524: 491: 483: 473: 471: 470: 465: 463: 459: 441: 437: 435: 434: 433: 421: 420: 407: 398: 396: 379: 374: 373: 341: 331: 324: 322: 321: 316: 285: 274:frequency domain 237: 224: 214: 208: 199: 197: 196: 191: 149: 147: 146: 141: 139: 131: 110: 99: 92: 88: 80: 73:coined the term 71:Oliver Heaviside 21: 1243: 1242: 1238: 1237: 1236: 1234: 1233: 1232: 1213: 1212: 1211: 1201: 1199: 1194: 1193: 1189: 1169: 1165: 1155: 1154: 1150: 1133: 1129: 1081: 1080: 1076: 1072: 1050: 1033: 1027: 1021: 1015: 965: 964: 949: 946: 940: 936: 915: 901: 882: 881: 858: 854: 827: 814: 805: 804: 791: 778: 757: 744: 735: 724: 715: 714: 696: 695: 678: 665: 664: 629: 623: 622: 605: 592: 591: 559: 547: 546: 540: 536: 496: 495: 489: 481: 446: 442: 425: 412: 411: 402: 383: 362: 351: 350: 339: 329: 288: 287: 283: 282:The impedance, 256: 232: 222: 212: 206: 163: 162: 119: 118: 108: 97: 90: 86: 78: 35: 28: 23: 22: 15: 12: 11: 5: 1241: 1239: 1231: 1230: 1225: 1215: 1214: 1210: 1209: 1187: 1163: 1148: 1127: 1090:(15): 155115. 1073: 1071: 1068: 1067: 1066: 1061: 1056: 1049: 1046: 1038: 1037: 1031: 1025: 1019: 1000: 996: 993: 990: 987: 984: 981: 978: 975: 972: 944: 935: 932: 928: 927: 913: 908:, measured in 880: 875: 869: 866: 861: 857: 853: 850: 847: 843: 838: 835: 830: 826: 823: 820: 817: 815: 813: 810: 807: 806: 798: 794: 790: 785: 781: 776: 771: 764: 760: 756: 751: 747: 741: 738: 736: 733: 730: 727: 723: 722: 694: 685: 681: 677: 672: 668: 663: 658: 655: 652: 649: 646: 642: 639: 635: 632: 630: 628: 625: 624: 621: 612: 608: 604: 599: 595: 590: 585: 582: 579: 576: 572: 569: 565: 562: 560: 558: 555: 554: 522: 518: 515: 512: 509: 506: 503: 462: 458: 455: 452: 449: 445: 440: 432: 428: 424: 419: 415: 410: 405: 401: 395: 392: 389: 386: 382: 377: 372: 369: 365: 361: 358: 348: 347: 337: 314: 310: 307: 304: 301: 298: 295: 280: 279: 255: 252: 244: 243: 240:imaginary unit 230: 229:(siemens); and 220: 210: 189: 185: 182: 179: 176: 173: 170: 137: 134: 129: 126: 111:, measured in 100:, measured in 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 1240: 1229: 1226: 1224: 1221: 1220: 1218: 1198: 1191: 1188: 1185: 1181: 1177: 1173: 1167: 1164: 1159: 1152: 1149: 1145: 1141: 1137: 1131: 1128: 1123: 1119: 1115: 1111: 1107: 1103: 1098: 1093: 1089: 1085: 1078: 1075: 1069: 1065: 1062: 1060: 1057: 1055: 1052: 1051: 1047: 1042: 1032: 1026: 1020: 1014: 1013: 1012: 998: 994: 991: 988: 985: 982: 979: 976: 973: 970: 957: 953: 943: 933: 931: 925: 921: 914: 911: 907: 900: 899: 898: 895: 878: 873: 867: 864: 859: 855: 851: 848: 845: 841: 836: 833: 828: 824: 821: 818: 816: 811: 796: 792: 788: 783: 779: 774: 769: 762: 758: 754: 749: 745: 739: 737: 731: 728: 725: 712: 709: 692: 683: 679: 675: 670: 666: 661: 656: 653: 647: 633: 631: 626: 619: 610: 606: 602: 597: 593: 588: 583: 577: 563: 561: 556: 544: 533: 520: 516: 513: 510: 507: 504: 501: 493: 487: 479: 474: 460: 456: 453: 450: 447: 443: 438: 430: 426: 422: 417: 413: 408: 403: 399: 393: 390: 387: 384: 380: 375: 370: 367: 363: 359: 356: 345: 338: 335: 328: 327: 326: 312: 308: 305: 302: 299: 296: 293: 277: 275: 271: 267: 263: 258: 257: 253: 251: 249: 241: 235: 231: 228: 221: 218: 211: 205: 204: 203: 200: 187: 183: 180: 177: 174: 171: 168: 160: 158: 154: 150: 135: 132: 127: 124: 116: 114: 107: 103: 94: 84: 76: 72: 68: 64: 60: 56: 52: 48: 44: 40: 33: 19: 1200:. Retrieved 1190: 1183: 1182:, Chapter 5 1171: 1166: 1157: 1151: 1135: 1130: 1087: 1083: 1077: 961: 941: 937: 929: 896: 713: 710: 545: 534: 494: 475: 349: 281: 259: 245: 233: 201: 161: 151: 117: 95: 74: 42: 36: 920:susceptance 906:conductance 336:(ohms); and 227:susceptance 217:conductance 96:Admittance 1217:Categories 1144:0801842980 1070:References 1064:Immittance 484:), and an 334:resistance 266:capacitors 219:(siemens); 153:Resistance 75:admittance 47:reciprocal 43:admittance 1122:119500762 989:ω 860:− 852:⁡ 825:⁡ 809:∠ 657:− 492:), thus: 486:imaginary 451:− 368:− 344:reactance 270:inductors 262:impedance 157:reactance 128:≡ 106:impedance 51:impedance 1048:See also 1102:Bibcode 924:siemens 918:is the 910:siemens 904:is the 897:where 346:(ohms). 342:is the 332:is the 225:is the 215:is the 202:where 102:siemens 63:siemens 1202:30 Apr 1178:  1142:  1120:  1011:where 849:arctan 822:arctan 535:where 325:where 238:, the 1118:S2CID 1092:arXiv 912:; and 1204:2018 1176:ISBN 1140:ISBN 948:and 478:real 268:and 236:= −1 113:ohms 1110:doi 67:mho 49:of 37:In 1219:: 1116:. 1108:. 1100:. 1088:68 1086:. 115:: 59:SI 41:, 1206:. 1146:. 1124:. 1112:: 1104:: 1094:: 1034:C 1028:l 1022:y 1016:Y 999:, 995:l 992:C 986:j 983:= 980:l 977:y 974:= 971:Y 950:B 945:c 942:G 926:. 916:B 902:G 879:, 874:) 868:R 865:X 856:( 846:= 842:) 837:G 834:B 829:( 819:= 812:Y 797:2 793:X 789:+ 784:2 780:R 775:1 770:= 763:2 759:B 755:+ 750:2 746:G 740:= 732:| 729:Y 726:| 693:. 684:2 680:X 676:+ 671:2 667:R 662:X 654:= 651:) 648:Y 645:( 641:m 638:I 634:= 627:B 620:, 611:2 607:X 603:+ 598:2 594:R 589:R 584:= 581:) 578:Y 575:( 571:e 568:R 564:= 557:G 541:B 537:G 521:, 517:B 514:j 511:+ 508:G 505:= 502:Y 490:B 482:G 461:) 457:X 454:j 448:R 444:( 439:) 431:2 427:X 423:+ 418:2 414:R 409:1 404:( 400:= 394:X 391:j 388:+ 385:R 381:1 376:= 371:1 364:Z 360:= 357:Y 340:X 330:R 313:, 309:X 306:j 303:+ 300:R 297:= 294:Z 284:Z 278:. 242:. 234:j 223:B 213:G 207:Y 188:, 184:B 181:j 178:+ 175:G 172:= 169:Y 136:Z 133:1 125:Y 109:Z 98:Y 91:Z 87:Y 79:Y 34:. 20:)

Index

Electrical admittance
Admittance (disambiguation)
electrical engineering
reciprocal
impedance
conductance and resistance
SI
siemens
mho
Oliver Heaviside
Charles Proteus Steinmetz
siemens
impedance
ohms
Resistance
reactance
conductance
susceptance
imaginary unit
universal dielectric response
impedance
capacitors
inductors
frequency domain
resistance
reactance
real
imaginary
conductance
siemens

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