// Numbas version: finer_feedback_settings
{"name": "Load Flow Analysis - 4bus", "extensions": [], "custom_part_types": [], "resources": [["question-resources/LF2Circuit_GJ385fH.png", "/srv/numbas/media/question-resources/LF2Circuit_GJ385fH.png"]], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"name": "Load Flow Analysis - 4bus", "tags": [], "metadata": {"description": "", "licence": "None specified"}, "statement": "<p style=\"text-align: left;\">For the following 4-bus system, bus 1 is the swing bus. Values are given in per-unit on a 10 MVA base:</p>\n<p style=\"text-align: center;\"><img src=\"resources/question-resources/LF2Circuit_GJ385fH.png\"/></p>\n<p></p>\n<table border=\"1\" style=\"margin-left: auto; margin-right: auto;\">\n<tbody>\n<tr>\n<td style=\"text-align: center;\">\n<p><strong>Bus</strong></p>\n</td>\n<td style=\"text-align: center;\">\n<p><strong>Power In</strong></p>\n</td>\n<td style=\"text-align: center;\">\n<p><strong>Power&nbsp;Out</strong></p>\n</td>\n<td style=\"text-align: center;\">\n<p><strong>Voltage</strong></p>\n</td>\n</tr>\n<tr>\n<td style=\"text-align: center;\">\n<p>1</p>\n</td>\n<td style=\"text-align: center;\">\n<p>?</p>\n</td>\n<td style=\"text-align: center;\">\n<p>0</p>\n</td>\n<td style=\"text-align: center;\">\n<p>1&nbsp;$\\angle $0</p>\n</td>\n</tr>\n<tr>\n<td style=\"text-align: center;\">\n<p>2</p>\n</td>\n<td style=\"text-align: center;\">\n<p>0</p>\n</td>\n<td style=\"text-align: center;\">\n<p>0</p>\n</td>\n<td style=\"text-align: center;\">\n<p>?</p>\n</td>\n</tr>\n<tr>\n<td style=\"text-align: center;\">\n<p>3</p>\n</td>\n<td style=\"text-align: center;\">\n<p>0</p>\n</td>\n<td style=\"text-align: center;\">\n<p>{P3}&nbsp;+ j {Q3}</p>\n</td>\n<td style=\"text-align: center;\">\n<p>?</p>\n</td>\n</tr>\n<tr>\n<td style=\"text-align: center;\">\n<p>4</p>\n</td>\n<td style=\"text-align: center;\">\n<p>0</p>\n</td>\n<td style=\"text-align: center;\">\n<p>{P4}&nbsp;+ j {Q4}</p>\n</td>\n<td style=\"text-align: center;\">\n<p>?</p>\n</td>\n</tr>\n</tbody>\n</table>\n<p style=\"text-align: center;\"><em><strong>&nbsp;Table 1: Bus information</strong></em></p>\n<p style=\"text-align: center;\"><em><strong></strong></em></p>\n<table border=\"1\" style=\"margin-left: auto; margin-right: auto;\">\n<tbody>\n<tr style=\"height: 43px;\">\n<td style=\"text-align: center; height: 43px;\">\n<p><strong>Section</strong></p>\n</td>\n<td style=\"text-align: center; height: 43px;\">\n<p><strong>Series Impedance</strong></p>\n</td>\n</tr>\n<tr style=\"height: 43px;\">\n<td style=\"text-align: center; height: 43px;\">\n<p>1-2</p>\n</td>\n<td style=\"text-align: center; height: 43px;\">\n<p>j {X12}</p>\n</td>\n</tr>\n<tr style=\"height: 43px;\">\n<td style=\"text-align: center; height: 43px;\">\n<p>2-3</p>\n</td>\n<td style=\"text-align: center; height: 43px;\">\n<p>j {X23}</p>\n</td>\n</tr>\n<tr style=\"height: 37.5742px;\">\n<td style=\"text-align: center; height: 37.5742px;\">2-4</td>\n<td style=\"text-align: center; height: 37.5742px;\">j {X24}</td>\n</tr>\n</tbody>\n</table>\n<p style=\"text-align: center;\"><em><strong>Table 2: Line information</strong></em></p>", "advice": "", "rulesets": {}, "extensions": [], "builtin_constants": {"e": true, "pi,\u03c0": true, "i": true}, "constants": [], "variables": {"Y": {"name": "Y", "group": "Computed", "definition": "matrix([Y12,-Y12,0,0],[-Y12,Y12+Y23+Y24,-Y23,-Y24],[0,-Y23,Y23,0],[0,-Y24,0,Y24])", "description": "", "templateType": 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