{ "node": { "id": "term:dc-dc-converter", "type": "Term", "label": "DC/DC converter", "properties": { "id": "dc-dc-converter", "name": "DC/DC converter", "section": "topic-pack", "definition": "The power electronics that step the high-voltage pack down to 12 V or 48 V for the auxiliary systems, replacing the alternator of a combustion car. Boost converters also appear between an 800 V pack and a 400 V charger.", "related": [ "auxiliary-battery", "inverter", "pack-voltage" ], "url": "https://lemonergy.com/learn/glossary/dc-dc-converter/", "mentions": [ "charger" ] } }, "edges": [ { "id": "edge:100", "source": "term:dc-dc-converter", "target": "workflow:v2v", "type": "usedIn", "properties": { "sourceFile": "wiki-blocks.json" } }, { "id": "edge:3066", "source": "term:dc-dc-converter", "target": "topic:topic-pack", "type": "belongsTo", "properties": { "sourceFile": "terms.json" } }, { "id": "edge:3067", "source": "term:dc-dc-converter", "target": "term:auxiliary-battery", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:3068", "source": "term:dc-dc-converter", "target": "term:inverter", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:3069", "source": "term:dc-dc-converter", "target": "term:pack-voltage", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:mentions/dc-dc-converter/charger", "source": "term:dc-dc-converter", "target": "term:charger", "type": "mentions", "properties": { "sourceFile": "terms.json", "method": "build_glossary.mention_index + mentions", "field": "definition", "meaning": "Text mention; not a causal claim" } }, { "id": "edge:3071", "source": "term:dc-dc-converter", "target": "visual:pwm", "type": "illustratedBy", "properties": { "sourceFile": "visual-pages.json" } } ], "neighbors": [ { "id": "workflow:v2v", "type": "Workflow", "label": "Transfer between two batteries", "properties": { "id": "v2v", "title": "Transfer between two batteries", "kind": "studio", "summary": "Conserving conversion couples donor and recipient.", "steps": [ "Inspect donor reserve and recipient target.", "Compare energy drawn and delivered." ], "example": "5 kW delivered at 90% efficiency needs about 5.56 kW from the donor and produces about 0.56 kW loss.", "observe": "Both islands have references and energy flows.", "limits": "The example assumes hardware compatibility; it does not establish connector or communication compatibility.", "url": "https://design.lemonergy.com/cosim.html?example=charging-v2v", "label": "Open the Studio example", "evidence": [ "js/charging-control.js", "js/charging-scenarios.js", "docs/CHARGING_BLOCKS_SPEC.md" ] } }, { "id": "topic:topic-pack", "type": "Topic", "label": "Modules, packs and battery management", "properties": { "id": "topic-pack", "name": "Modules, packs and battery management", "lede": "From a single cell to a working battery system, and the electronics that keep it safe.", "context": "Make series/parallel architecture explicit.", "example": "Twelve 3.6 V, 5 Ah cells in 6s2p give 21.6 V, 10 Ah and 216 Wh nominally before other restrictions.", "lesson_url": "https://lemonergy.com/learn/fundamentals/cell-architecture/", "lesson_label": "Open cell architecture" } }, { "id": "term:auxiliary-battery", "type": "Term", "label": "Auxiliary battery", "properties": { "id": "auxiliary-battery", "name": "Auxiliary battery", "aka": [ "12 V battery", "low-voltage battery" ], "section": "topic-pack", "definition": "The small 12 V or 48 V battery in an electric vehicle that powers the controllers, lights and locks and wakes the BMS, kept charged from the high-voltage pack through a DC/DC converter. A flat auxiliary battery immobilises the car however full the main pack is.", "related": [ "dc-dc-converter", "lead-acid", "pack", "lin-bus" ], "url": "https://lemonergy.com/learn/glossary/auxiliary-battery/", "mentions": [ "bms", "electric-vehicle" ] } }, { "id": "term:inverter", "type": "Term", "label": "Inverter", "properties": { "id": "inverter", "name": "Inverter", "aka": [ "power conversion system", "PCS" ], "section": "topic-pack", "definition": "The power electronics that turn the battery’s DC into AC for a motor or the grid, and back again for charging. In stationary storage it is called the power conversion system and its rating in kW or MW sets the system’s power independently of the battery’s energy.", "related": [ "pre-charge", "dc-dc-converter", "stationary-storage", "energy-management-system", "direct-current", "iec-62477-1" ], "url": "https://lemonergy.com/learn/glossary/inverter/", "mentions": [] } }, { "id": "term:pack-voltage", "type": "Term", "label": "Pack voltage", "properties": { "id": "pack-voltage", "name": "Pack voltage", "aka": [ "400 V system", "800 V system" ], "section": "topic-pack", "definition": "The nominal voltage of the full series string, about 400 V in most electric cars and 800 V in newer ones. Doubling the voltage halves the current for the same power, so cables, connectors and losses shrink and charging can be faster.", "unit": "V", "related": [ "series-parallel", "dc-fast-charging", "high-voltage-interlock", "insulation-resistance" ], "url": "https://lemonergy.com/learn/glossary/pack-voltage/", "mentions": [ "nominal-voltage", "string" ] } }, { "id": "term:charger", "type": "Term", "label": "Charger", "properties": { "id": "charger", "name": "Charger", "section": "topic-charging", "definition": "The power electronics that convert mains or DC supply into the controlled current and voltage a battery needs. For lithium-ion it runs the CC-CV profile within the limits the BMS communicates, and stops rather than floats when the cell is full.", "related": [ "cc-cv-charging", "bms", "onboard-charger", "dc-fast-charging" ], "url": "https://lemonergy.com/learn/glossary/charger/", "mentions": [] } }, { "id": "visual:pwm", "type": "Visual", "label": "Duty cycle controls average voltage", "properties": { "title": "Duty cycle controls average voltage", "summary": "An ideal pulse train alternates between zero and the supply voltage.", "readout": "50% of 12 V gives a 6 V time average.", "formula": "V_average = D V_supply", "note": "Unfiltered ideal waveform; actual output depends on the converter circuit and control.", "software": { "status": "reference", "label": "Reference concept", "body": "This shows V_avg = duty × V_supply for a pulse train. A real converter also requires topology, filtering, switching losses and control.", "href": "../chapter-1/" }, "html": "
Ideal 12 V pulse train
Ideal 12 V pulse trainTime (switching periods) versus Voltage (V). Switched voltage; Time average. Interpretation follows the graphs.003.517210.53144Time (switching periods)Voltage (V)
Switched voltageTime average (dashed)
" } } ] }