{"schemaVersion":1,"slug":"microgrid-voltage-support-reserve-indication","name":"Microgrid voltage-support reserve indication","kind":"symbol","abbreviation":"MVRI","aliases":["Microgrid voltage and reactive-power controls","microgrids Microgrid voltage and reactive-power controls","microgrids","Microgrids","Resource reactive capability and output","Voltage-support headroom"],"category":"microgrid-systems","drawingTypes":["Schematic"],"referenceFamilies":["Manufacturer"],"summary":"Identifies the declared remaining resource capability for assigned voltage-support action.","description":["Identifies the declared remaining resource capability for assigned voltage-support action. Voltage and reactive-power control coordinate the AC operating condition of the microgrid resources. A voltage target, reactive-power target and power-factor target represent different control objectives and should have explicit ownership.","In an islanded microgrid, the assigned reference source supports bus voltage while other compatible resources share reactive demand according to the selected control method. Grid-connected operation can use a different objective at the PCC. For this reference, the drawing identifies “Resource reactive capability and output” at the input and “Voltage-support headroom” at the output. Headroom is not guaranteed disturbance performance.","Show each measured quantity, target and resource capability limit. Control-loop tuning, equipment capability and parallel operation require a validated design rather than an assumed property of the symbol. The functional block is an independent explanation of this named application. Equipment-specific ratings, terminal connections and operating conditions must be established in the project documentation."],"readingNotes":["Start at the named input: Resource reactive capability and output. Identify its source device or document and the state represented on the drawing.","Follow the named output: Voltage-support headroom. Cross-reference its destination and separate the command from confirmation that the equipment responded.","Headroom is not guaranteed disturbance performance.","Show each measured quantity, target and resource capability limit. Control-loop tuning, equipment capability and parallel operation require a validated design rather than an assumed property of the symbol."],"drawingChecklist":["Label the source and connection reference for resource reactive capability and output.","Identify the destination and defined state of voltage-support headroom.","Record the equipment or control-document revision supporting this functional block.","Check this application limit in the project design: Headroom is not guaranteed disturbance performance."],"distinction":"Headroom is not guaranteed disturbance performance. This reference describes the named application; it does not establish a new IEC graphical symbol, an ANSI device-function number or an exact manufacturer connection diagram.","facts":[{"label":"Representation","value":"Functional block"},{"label":"Installation focus","value":"Microgrids"},{"label":"Input / boundary","value":"Resource reactive capability and output"},{"label":"Output / connection","value":"Voltage-support headroom"},{"label":"Lookup label","value":"MVRI is a library lookup label, not a standard device designation."}],"references":[{"sourceId":"pi26-mg-power","relevance":"Public technical context for microgrid voltage and reactive-power controls. Active and reactive power, generation, load control, operating reserves and system supervision. The application text and educational graphic are independently authored; the publisher does not certify this representation."}],"related":["grid-forming-inverter","statcom","microgrid-capacitor-step-coordination-request"],"artwork":"pi26-microgrid-voltage-support-reserve-indication","publishedOn":"2026-11-03","updatedOn":"2026-11-03","provenance":"independent-public-research","representation":{"type":"functional-block","focus":"microgrids","family":"microgrid-reactive","input":"Resource reactive capability and output","output":"Voltage-support headroom"},"plainEnglish":{"title":"What this block does","introduction":"Identifies the declared remaining resource capability for assigned voltage-support action.","example":"In an islanded microgrid, the assigned reference source supports bus voltage while other compatible resources share reactive demand according to the selected control method. Grid-connected operation can use a different objective at the PCC. For this reference, the drawing identifies “Resource reactive capability and output” at the input and “Voltage-support headroom” at the output. Headroom is not guaranteed disturbance performance.","drawings":"Start at the named input: Resource reactive capability and output. Identify its source device or document and the state represented on the drawing. Follow the named output: Voltage-support headroom. Cross-reference its destination and separate the command from confirmation that the equipment responded.","terms":[{"name":"Input","meaning":"Resource reactive capability and output"},{"name":"Output","meaning":"Voltage-support headroom"},{"name":"Application reference","meaning":"An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections."}],"diagram":"flow","steps":["Resource reactive capability and output","MVRI","Voltage-support headroom"],"caption":"A reading guide. The entry's original illustration and input/output facts describe this application.","sources":[{"label":"Microgrid control systems","url":"https://selinc.com/services/microgrids-power-management/microgrid-control-systems/"}],"profileId":"power-installation-microgrid-reactive"},"url":"https://eloragrid.ai/symbols/microgrid-voltage-support-reserve-indication","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/microgrid-voltage-support-reserve-indication.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"pi26-mg-power","publisher":"SEL","title":"Microgrid control systems","url":"https://selinc.com/services/microgrids-power-management/microgrid-control-systems/","scope":"Active and reactive power, generation, load control, operating reserves and system supervision.","type":"manufacturer","checkedOn":"2026-11-03","reuse":"link-only","relevance":"Public technical context for microgrid voltage and reactive-power controls. Active and reactive power, generation, load control, operating reserves and system supervision. The application text and educational graphic are independently authored; the publisher does not certify this representation."}]}