// Numbas version: finer_feedback_settings
{"name": "Fault Analysis 4 Bus", "extensions": [], "custom_part_types": [], "resources": [["question-resources/FA4Bus.png", "/srv/numbas/media/question-resources/FA4Bus.png"]], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"name": "Fault Analysis 4 Bus", "tags": [], "metadata": {"description": "", "licence": "None specified"}, "statement": "<p style=\"text-align: center;\">In the system shown in <strong>Figure 1</strong>, the transformers&nbsp;are connected star-star with both star points grounded and the generators&nbsp;are connected in star with thier star points grounded. The per unit sequence reactances of each element on a {SBASE} MVA base are given in <strong>Table 1</strong>.</p>\n<p style=\"text-align: center;\">{image('resources/question-resources/FA4Bus.png')}</p>\n<p style=\"text-align: center;\"><strong><em>Figure 1: A section of the distribution system</em></strong></p>\n<table border=\"1\" cellpadding=\"1\" style=\"margin-left: auto; margin-right: auto;\">\n<tbody>\n<tr>\n<td width=\"74\" style=\"text-align: center;\">\n<p>&nbsp;</p>\n</td>\n<td width=\"74\" style=\"text-align: center;\">\n<p><strong>G1</strong></p>\n</td>\n<td width=\"74\" style=\"text-align: center;\">\n<p><strong>T1</strong></p>\n</td>\n<td width=\"74\" style=\"text-align: center;\">\n<p style=\"text-align: center;\"><strong>L</strong></p>\n</td>\n<td width=\"74\" style=\"text-align: center;\">\n<p style=\"text-align: center;\"><strong>T2</strong></p>\n</td>\n<td width=\"74\" style=\"text-align: center;\">\n<p style=\"text-align: center;\"><strong>G2</strong></p>\n</td>\n</tr>\n<tr>\n<td width=\"74\" style=\"text-align: center;\">\n<p><strong>X<sub>1</sub></strong></p>\n</td>\n<td width=\"74\" style=\"text-align: center;\">\n<p>{G112}</p>\n</td>\n<td width=\"74\" style=\"text-align: center;\">\n<p>{T1}</p>\n</td>\n<td width=\"74\" style=\"text-align: center;\">\n<p>{L12}</p>\n</td>\n<td width=\"74\" style=\"text-align: center;\">\n<p>{T2}</p>\n</td>\n<td width=\"74\" style=\"text-align: center;\">\n<p>{G212}</p>\n</td>\n</tr>\n<tr>\n<td width=\"74\" style=\"text-align: center;\">\n<p><strong>X<sub>2</sub></strong></p>\n</td>\n<td width=\"74\" style=\"text-align: center;\">\n<p>{G112}</p>\n</td>\n<td width=\"74\" style=\"text-align: center;\">\n<p>{T1}</p>\n</td>\n<td width=\"74\" style=\"text-align: center;\">\n<p>{L12}</p>\n</td>\n<td width=\"74\" style=\"text-align: center;\">\n<p>{T2}</p>\n</td>\n<td width=\"74\" style=\"text-align: center;\">\n<p>{G212}</p>\n</td>\n</tr>\n<tr>\n<td width=\"74\" style=\"text-align: center;\">\n<p><strong>X<sub>0</sub></strong></p>\n</td>\n<td width=\"74\" style=\"text-align: center;\">\n<p>{G10}</p>\n</td>\n<td width=\"74\" style=\"text-align: center;\">\n<p>{T1}</p>\n</td>\n<td width=\"74\" style=\"text-align: center;\">\n<p>{L0}</p>\n</td>\n<td width=\"74\" style=\"text-align: center;\">\n<p>{T2}</p>\n</td>\n<td width=\"74\" style=\"text-align: center;\">\n<p>{G20}</p>\n</td>\n</tr>\n</tbody>\n</table>\n<p style=\"text-align: center;\"><em><strong></strong></em><em><strong>&nbsp;Table 1: Sequence reactances (p.u. on {SBASE} MVA base)</strong></em></p>", "advice": "", "rulesets": {}, "extensions": [], "variables": {"G112": {"name": "G112", "group": "Ungrouped variables", "definition": "random(0.05 .. 0.2#0.01)", "description": "", "templateType": "randrange"}, "G10": {"name": "G10", "group": "Ungrouped variables", "definition": "precround(ratio*G112,2)", "description": "", "templateType": "anything"}, "L0": {"name": "L0", "group": "Ungrouped 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"nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p>If a&nbsp;single-phase fault occurs at bus&nbsp;3 with a fault reactance of {XF} p.u. calculate the fault current flowing&nbsp;at the fault point (in p.u.).</p>\n<p>$ I_F $ = -j&nbsp;[[0]] &nbsp;p.u.</p>", "gaps": [{"type": "numberentry", "useCustomName": true, "customName": "IFpu", "marks": "10", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "0.999*IFpu", "maxValue": "1.001*IFpu", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}], "sortAnswers": false}, {"type": "gapfill", "useCustomName": true, "customName": "Voltage", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p>What are the voltages on each phase at the fault point (in p.u.) after the fault occurs? (Assume the fault is on the A-phase)</p>\n<p>$ V_A $ =&nbsp;[[0]] $\\angle \\ 0 \\ ^o $&nbsp;&nbsp;p.u.</p>\n<p>$ V_B $ =&nbsp;[[1]]&nbsp;$\\angle$&nbsp; [[2]]&nbsp;p.u.</p>\n<p>$ V_C $ =&nbsp; [[3]]&nbsp;$\\angle$&nbsp;[[4]]&nbsp;p.u.</p>", "gaps": [{"type": "numberentry", "useCustomName": true, "customName": "VA", "marks": "2", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "0.999*VA", "maxValue": "1.001*VA", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "numberentry", "useCustomName": true, "customName": "VB", "marks": "2", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "0.999*VB", "maxValue": "1.001*VB", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "numberentry", "useCustomName": true, "customName": "deltaB", "marks": "2", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "0.99*deltaB", "maxValue": "1.01*deltaB", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "numberentry", "useCustomName": true, "customName": "VC", "marks": "2", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "0.999*VC", "maxValue": "1.001*VC", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "numberentry", "useCustomName": true, "customName": "deltaC", "marks": "2", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "0.99*deltaC", "maxValue": "1.01*deltaC", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}], "sortAnswers": false}], "partsMode": "all", "maxMarks": 0, "objectives": [], "penalties": [], "objectiveVisibility": "always", "penaltyVisibility": "always", "type": "question", "contributors": [{"name": "Jane Courtney", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/2154/"}]}]}], "contributors": [{"name": "Jane Courtney", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/2154/"}]}