Transformador QDTB®

Calculadora de Dimensionamento e Preços de Sistemas Solares

Dimensione o conjunto PV, o inversor, a bateria e os cabos para solar residencial ou C&I — com recurso solar baseado em mapa, produção probabilística P50/P75/P90 e economia de custo total (LCOE, retorno, IRR, NPV).

Começar a Calcular
Pesquise um local ou clique no mapa — preenche automaticamente a latitude e o recurso solar.
P50 = ano mediano; P75/P90 são níveis de excedência bancáveis a partir da variabilidade solar interanual.
Parâmetros avançados
Os valores predefinidos correspondem à base de dimensionamento padrão — ajuste para condições específicas do local.

Como funciona

Escolha a aplicação e introduza a potência do sistema. A calculadora dimensiona a string, o inversor e a bateria, dimensiona o cabo CC para queda de tensão e estima a produção anual — depois calcula o preço da BOM e executa um modelo económico de custo total.

Worked Examples

Example 1 — 200 kW C&I Grid-Tie Solar (10 kV) · FOB $78,739
Solar system · iec standard · P50/P75/P90
333,461 kWh/yr (P50)
PR 0.846 · P75 324,471 · P90 316,361 kWh/yr
LCOE (full-cost)
$0.0620/kWh
Payback
4.9 yr
Est. total (FOB)
$78,739
💰 Full-cost economics (P50)
ParameterValue
LCOE$0.0620/kWh (O&M + WACC + inverter replacement + degradation)
Simple payback4.9 yr
IRR / NPV19.8% / $165,229
DSCR2.31
☀️ Generation (P50/P75/P90)
ParameterValue
P50 yield333,461 kWh/yr
P75 yield324,471 kWh/yr
P90 yield316,361 kWh/yr (bankable)
Interannual CV4.0% · climatology (typical interannual CV assumption)
📦 Bill of Materials (example)
EquipmentModelSpecQty
PV Modules550Wp Mono437
String Inverter110kW + 100kW2
DC Combiner Box17 inputs1
DC Distribution PanelQDTB1
PV Mountingcolor-steel / flat roof · tilt 25.9°1
DC Cable PV1-F 6mm²ΔU 0.2% @ 30m525
MC4 Connectormale/female pair471
AC CableYJV 4x150180
Cable Trayhot-dip galvanized30
DC Surge Protector40kA 1000V4
Protection RelayOC/instantaneous/anti-islanding1
SCADA Monitoringplant-level1
Earthing Systemflat bar + rods1
Step-Up Box Substation250kVA 10kV1
HV SwitchgearKYN28-121
Ring Main UnitSF6 630A1
Summary
Estimated total (FOB Qingdao, EXW) — priced equipment$78,739
📐 Single-line diagram
PV ARRAY240.0 kWp - 28 stringsDC 1000VCombiner437 inInverter110kW+100kWkWAC 400VLV PanelGCK250kVA10kVHV PanelKYN28RMUSF6GRID 10kVLEGENDBreakerCTCT (current transformer)PTPT (voltage transformer)50/51Relay 50/51/51NkWhMeter (kWh)SPD (surge protection)
⚙️ Electrical schematic (protection & metering)
SYSTEM ELECTRICAL SCHEMATIC - C&I GRID-TIED (3-PHASE)1 - PV ARRAY2 - DC COMBINER3 - INVERTERS4 - AC PROTECT5 - GRID6 - SCADA / COMMS7 - EARTHING / PE240 kWp437 mod - 2 stringscombiner (per-string fuse)DC SPDMPPT3-PHASE BRIDGE (x2 inv)LC filterBreakercontactor + anti-islanding relayGRID10kVstep-up box sub250 kVAkWhCTCT .../5APTPT kV/100V50/51relaySCADA + Relayplant-level - RS485EMS / SCADA commsPE bus PV frames - combiner - inverter - transformer - switchgear
⛳ Grounding grid layout
SUBSTATION GROUNDING GRID LAYOUTsite 60 m x 49 m - ring earth electrode (schematic)SOLAR PLANTR1R2R3R4R5R6R7R8R9R10R11R12R13R14R15R16R17R18R19R20R21R22R23R24R25R26R27R28R29R30R31R32R33R34R35R36R37R38R39R40R41R42R43R4460 mGround rods: 44 x dia 16 mm x 2.5 m copper-bonded steelRod spacing: 5 m (= 2 x rod length, ring electrode)Target resistance: <= 4 ohm (measure after installation)Standard: IEEE 80 / GB-T 50065 (earthing design) - indicative layout
🔌 Cable schedule & routing
CABLE SCHEDULE - SOLAR PLANTIDFromToCable (model / spec)LengthDC117 PV stringsDC combiner6 mm2 PV1-F (DC)96 mAC1Inverter 210 kWAC distribution panelYJV 0.6/1kV - 289 A48 mMV1AC panel250 kVA step-upYJV 8.7/15kV120 mPOIStep-up transformerGrid (POI)10 kV interconnection72 mROUTING (schematic)LV PANELL1L2L3L4Cable lengths are indicative (run-length based); confirm on site before installation.
🗄 Switchgear arrangement
SWITCHGEAR ARRANGEMENT - SOLAR PLANTpanel lineup (front view, schematic)INV210 kWACdistributionTR250 kVAPOI10 kV4 panel(s) - each 160 mm (typical)Clearance / aisle per IEC 61936-1 - layout indicative
🛡 Protection configuration
PROTECTION CONFIGURATION - PV PLANT240 kWp - 17 strings - protection zones (schematic)PV ARRAY 240 kWpFDC fuse 20 A / stringDC SPD (Type 2)INV210 kW50/51 + anti-islanding52 - 361 A - 400 VSTEP-UP 250 kVA8749differential + thermal50/51HV overcurrent52GRID (POI)400 VearthingProtection layout is schematic / illustrative final settings per IEC 60255 / IEEE 1547 / IEC 60364.
📋 Protection settings
CircuitProtectionSettingTimeStandard
PV string (DC)gPV fuse20 AinstIEC 60269-6
DC sideSPD (surge)Type 2 - 40 kAinstIEC 61643-11
Inverter AC output50/51 + anti-islanding318 A0.1 sIEEE 1547 / IEC 62116
Step-up transformer 250 kVA87 differential58 AinstIEEE C37.91 / GB/T 14285
Step-up transformer 250 kVA50/51 overcurrent347 A0.3 sIEC 60255-151
Grid interconnection (POI)anti-islanding / ROCOFper grid codeper grid codeIEEE 1547 / IEC 61727
Settings are illustrative starting points — confirm with a protection coordination study per IEC 60255 / IEEE 242.
📚 Calculation book
CALCULATION BOOK
Solar cni-grid - 240 kWp - iec - illustrative
1. PV array
Standard: IEC 62548 (PV array design)
ParameterFormulaValue
Array capacityPpv = kW x oversize240 kWp
ModulesN = Ppv / Wmodule437 pcs
StringsS = N / ns17 strings
2. String design (temp-corrected)
Standard: IEC 60364-5-52
ParameterFormulaValue
Modules/string rangenMin - nMax6 - 27 modules
Cold VocVoc x ns @ Tmin55.4 V
Hot VmpVmp x ns @ Tmax36.6 V
3. DC voltage drop
Standard: IEC 60364-5-52
ParameterFormulaValue
DC dropdU = I x L x R / V0.2% (<= 2%)
DC cablesection6 mm2 PV1-F
4. AC interconnection
Standard: IEEE 1547 / IEC 61727
ParameterFormulaValue
Output currentI = P / (sqrt(3) x V)289 A
Interconnectionvoltage levelstep-up to 10 kV (250 kVA box sub)
5. Performance & generation
Standard: IEC 61724 (PV monitoring)
ParameterFormulaValue
Performance ratioPR = product of losses0.846
Annual yield (P50)Ppv x H x 365 x PR333,461 kWh/yr
P90 (bankable)P50 x (1 - 1.282 x CV)0 kWh/yr
This calculation book is illustrative values consolidate the computed results with the referenced standards. A licensed engineer must verify and seal final design documents.
🔧 Secondary schematic (control & signal)
SECONDARY CONTROL & SIGNAL CIRCUIT400 kV circuit breaker close/trip + indication + interlock (TYPICAL)+control supplyCS (close)interlock52Cclose coil-TC (trip)prot trip52Ttrip coilSIGNAL (indication)52a (closed)REDbreaker closed-TYPICAL CIRCUITStandard control/signal scheme for INVERTER AC FEEDER.Project detailing required (wiring, terminal assignment).
🔩 Terminal strip (typical)
TERMINAL STRIP (TYPICAL)X1 secondary wiring terminals (typical project detailing required)TerminalFunctionWireX1:1control supply L+1.5 mm2X1:2control supply L-1.5 mm2X1:3close command1.5 mm2X1:4trip command1.5 mm2X1:5breaker 52a status1.5 mm2X1:6breaker 52b status1.5 mm2X1:7trip circuit healthy1.5 mm2X1:8earth / shield2.5 mm2
📏 Standard basis (依据标准)
TopicStandard
Standard basisIEC
DC cable ampacityIEC 60364-5-52 Table B.52.2–B.52.5 (copper, 3 loaded conductors, 30°C ambient, PVC) — typical/rounded values, conservative (±3%)
Voltage-drop limitIEC 60364-5-52 Annex G (DC drop ≤ 2%)
String temp correctionIEC 60364-5-52 (temp -10°C / 60°C)
Unitsmm²
🧮 How it was calculated
1. PV capacity: 200kW x 1.2 = 240.0 kWp
2. Inverter: 110kW + 100kW (parallel)
3. String design: 17 strings x ~26 modules (temp-corrected 6-27/string)
4. DC voltage drop: 0.2% (PV1-F 6mm², 30m run)
5. Mounting: tilt 25.9° · row spacing 3.4m
6. Performance ratio (PR): 0.98 soiling x 0.97 mismatch x 0.98 wiring x 0.987 inverter x 0.92 temp = 0.846
7. Output current: ~ 289A (3-ph 400V)
8. Interconnection: step-up 10kV (box sub 250kVA)
9. LCOE (full-cost): $0.0620/kWh over 25 yr (O&M + WACC + inverter replacement + degradation)
10. Turnkey cost: FOB 78,739 → installed 152,048 (42% soft + 12% landing)
11. Payback / IRR / NPV: 4.9 yr · IRR 19.8% · NPV $165,229 · DSCR 2.31
Example 2 — 10 kW Residential Grid-Tie Solar · FOB $3,282
Solar system · iec standard · P50/P75/P90
15,860 kWh/yr (P50)
PR 0.836 · P75 15,433 · P90 15,047 kWh/yr
LCOE (full-cost)
$0.0686/kWh
Payback
5.4 yr
Est. total (FOB)
$3,282
💰 Full-cost economics (P50)
ParameterValue
LCOE$0.0686/kWh (O&M + WACC + inverter replacement + degradation)
Simple payback5.4 yr
IRR / NPV17.6% / $6,433
DSCR2.08
☀️ Generation (P50/P75/P90)
ParameterValue
P50 yield15,860 kWh/yr
P75 yield15,433 kWh/yr
P90 yield15,047 kWh/yr (bankable)
Interannual CV4.0% · climatology (typical interannual CV assumption)
📦 Bill of Materials (example)
EquipmentModelSpecQty
PV Modules550Wp Mono24
Grid-Tied String Inverter10kW1
PV Mounting (rooftop)13kWp · tilt 25.9°1
DC Cable PV1-F 4mm²ΔU 0.5% @ 30m36
MC4 Connectormale/female pair28
DC Surge Protector40kA 1000V2
AC Distribution Boxbreaker/SPD/anti-islanding1
Monitoring ModuleWiFi/4G APP1
Mounting Accessoriesclamps/bolts/earthing24
Summary
Estimated total (FOB Qingdao, EXW) — priced equipment$3,282
📐 Single-line diagram
PV ARRAY13.0 kWp - 2 stringsDC 1000VInverter10kWAC Dist. Boxbreaker/SPDGRID 220VLEGENDBreakerCTCT (current transformer)PTPT (voltage transformer)50/51Relay 50/51/51NkWhMeter (kWh)SPD (surge protection)
⚙️ Electrical schematic (protection & metering)
SYSTEM ELECTRICAL SCHEMATIC - RESIDENTIAL GRID-TIED (1-PHASE)1 - PV ARRAY2 - DC SIDE3 - INVERTER4 - AC SIDE5 - GRID6 - MONITORING7 - EARTHING / PE13.0 kWp24 mod - 2 stringsFuseDC SPDMPPTH-BRIDGELC filterBreakerAC SPDcontactor + anti-islandingUTILITY GRID220V / 50HzkWhbidirectional meterCTCT .../5APTPT50/51relayMonitoring ModuleWiFi / 4GRS485 / WiFi commsPE bus (TN-S) PV frames - inverter chassis - SPDs - meter
⛳ Grounding grid layout
SUBSTATION GROUNDING GRID LAYOUTsite 20 m x 15 m - ring earth electrode (schematic)SOLAR PLANTR1R2R3R4R5R6R7R8R9R10R11R12R13R1420 mGround rods: 14 x dia 16 mm x 2.5 m copper-bonded steelRod spacing: 5 m (= 2 x rod length, ring electrode)Target resistance: <= 4 ohm (measure after installation)Standard: IEEE 80 / GB-T 50065 (earthing design) - indicative layout
🔌 Cable schedule & routing
CABLE SCHEDULE - SOLAR PLANTIDFromToCable (model / spec)LengthDC12 PV stringsDC combiner4 mm2 PV1-F (DC)20 mAC1Inverter 10 kWAC distribution panelYJV 0.6/1kV - 14 A15 mPOIAC panelGrid (POI)380 V interconnection30 mROUTING (schematic)LV PANELL1L2L3Cable lengths are indicative (run-length based); confirm on site before installation.
🗄 Switchgear arrangement
SWITCHGEAR ARRANGEMENT - SOLAR PLANTpanel lineup (front view, schematic)INV10 kWACdistributionPOI380 V3 panel(s) - each 213 mm (typical)Clearance / aisle per IEC 61936-1 - layout indicative
🛡 Protection configuration
PROTECTION CONFIGURATION - PV PLANT13 kWp - 2 strings - protection zones (schematic)PV ARRAY 13 kWpFDC fuse 20 A / stringDC SPD (Type 2)INV10 kW50/51 + anti-islanding52 - 18 A - 380 VGRID (POI)380 VearthingProtection layout is schematic / illustrative final settings per IEC 60255 / IEEE 1547 / IEC 60364.
📋 Protection settings
CircuitProtectionSettingTimeStandard
PV string (DC)gPV fuse20 AinstIEC 60269-6
DC sideSPD (surge)Type 2 - 40 kAinstIEC 61643-11
Inverter AC output50/51 + anti-islanding15 A0.1 sIEEE 1547 / IEC 62116
Grid interconnection (POI)anti-islanding / ROCOFper grid codeper grid codeIEEE 1547 / IEC 61727
Settings are illustrative starting points — confirm with a protection coordination study per IEC 60255 / IEEE 242.
📚 Calculation book
CALCULATION BOOK
Solar res-grid - 13 kWp - iec - illustrative
1. PV array
Standard: IEC 62548 (PV array design)
ParameterFormulaValue
Array capacityPpv = kW x oversize13 kWp
ModulesN = Ppv / Wmodule24 pcs
StringsS = N / ns2 strings
2. String design (temp-corrected)
Standard: IEC 60364-5-52
ParameterFormulaValue
Modules/string rangenMin - nMax3 - 18 modules
Cold VocVoc x ns @ Tmin55.4 V
Hot VmpVmp x ns @ Tmax36.6 V
3. DC voltage drop
Standard: IEC 60364-5-52
ParameterFormulaValue
DC dropdU = I x L x R / V0.5% (<= 2%)
DC cablesection4 mm2 PV1-F
4. AC interconnection
Standard: IEEE 1547 / IEC 61727
ParameterFormulaValue
Output currentI = P / (sqrt(3) x V)14 A
Interconnectionvoltage level380 V direct
5. Performance & generation
Standard: IEC 61724 (PV monitoring)
ParameterFormulaValue
Performance ratioPR = product of losses0.836
Annual yield (P50)Ppv x H x 365 x PR15,860 kWh/yr
P90 (bankable)P50 x (1 - 1.282 x CV)0 kWh/yr
This calculation book is illustrative values consolidate the computed results with the referenced standards. A licensed engineer must verify and seal final design documents.
🔧 Secondary schematic (control & signal)
SECONDARY CONTROL & SIGNAL CIRCUIT400 kV circuit breaker close/trip + indication + interlock (TYPICAL)+control supplyCS (close)interlock52Cclose coil-TC (trip)prot trip52Ttrip coilSIGNAL (indication)52a (closed)REDbreaker closed-TYPICAL CIRCUITStandard control/signal scheme for INVERTER AC FEEDER.Project detailing required (wiring, terminal assignment).
🔩 Terminal strip (typical)
TERMINAL STRIP (TYPICAL)X1 secondary wiring terminals (typical project detailing required)TerminalFunctionWireX1:1control supply L+1.5 mm2X1:2control supply L-1.5 mm2X1:3close command1.5 mm2X1:4trip command1.5 mm2X1:5breaker 52a status1.5 mm2X1:6breaker 52b status1.5 mm2X1:7trip circuit healthy1.5 mm2X1:8earth / shield2.5 mm2
📏 Standard basis (依据标准)
TopicStandard
Standard basisIEC
DC cable ampacityIEC 60364-5-52 Table B.52.2–B.52.5 (copper, 3 loaded conductors, 30°C ambient, PVC) — typical/rounded values, conservative (±3%)
Voltage-drop limitIEC 60364-5-52 Annex G (DC drop ≤ 2%)
String temp correctionIEC 60364-5-52 (temp -10°C / 60°C)
Unitsmm²
🧮 How it was calculated
1. PV capacity: 10kW x 1.3 = 13.0 kWp
2. Module count: 13000Wp / 550W = 24 pcs
3. String design: 2 strings x ~12 modules
4. String limits: temp-corrected 3-18 modules/string (Voc 55.4V cold / Vmp 36.6V hot)
5. DC voltage drop: 0.5% (PV1-F 4mm², 30m run)
6. Mounting: tilt 25.9° · row spacing 3.4m
7. Performance ratio (PR): 0.98 soiling x 0.97 mismatch x 0.98 wiring x 0.975 inverter x 0.92 temp = 0.836
8. Inverter: nearest rating 10kW
9. LCOE (full-cost): $0.0686/kWh over 25 yr (O&M + WACC + inverter replacement + degradation)
10. Turnkey cost: FOB 3,282 → installed 7,352 (50% soft + 12% landing)
11. Payback / IRR / NPV: 5.4 yr · IRR 17.6% · NPV $6,433 · DSCR 2.08

Como foi calculado

Base de dimensionamento

Produção anual = potência CC × horas de sol de pico × 365 × razão de desempenho; P75/P90 = P50 × (1 − 0,674/1,282 × CV) a partir da irradiância interanual; LCOE é de custo total — (CAPEX + Σ(O&M + substituição do inversor) descontado) ÷ Σ(produção descontada).

Normas aplicáveis

O dimensionamento segue a IEC 60364-5-52 (ou NEC) para ampacidade e queda de tensão do cabo CC, com a janela MPPT do inversor verificada pela tensão da string corrigida pela temperatura; cada resultado é anotado com a sua referência normativa.

Perguntas frequentes

What is the difference between P50, P75 and P90 solar yield?

P50, P75 and P90 are exceedance-probability energy estimates accounting for interannual weather variability. P50 is the median year (50% chance of exceeding), P90 is exceeded in 90% of years and is the conservative 'bankable' value lenders require. With a typical interannual CV of 4-6%, P90 is roughly 7-10% below P50. The calculator reports all three plus LCOE.

How is LCOE calculated for a solar system?

LCOE divides lifetime discounted costs (capex, O&M, WACC financing, inverter replacement, module degradation) by lifetime discounted energy. The calculator uses a full-cost model: 25-year life, 0.5%/yr module degradation, WACC around 6-8%, and O&M about 1-1.5% of capex yearly. A 200 kW C&I system in a 4.5 sun-hour site typically lands near $0.04-0.06/kWh.

What tilt angle maximizes annual PV yield?

For a fixed-tilt array, annual yield is near-optimal when tilt equals the site latitude, typically latitude minus 5-15 degrees in low latitudes to favour summer load, or latitude plus 10-15 degrees for winter-heavy or off-grid loads. At 30 deg latitude the optimum is roughly 25-35 degrees. The calculator's yield model accounts for tilt, azimuth and local irradiation.

How many kWh per year does a 100 kW solar system generate?

Annual energy is roughly system kW x peak-sun-hours x performance ratio. A 100 kW array in a 4.5 sun-hour region with a PR of 0.78-0.82 yields about 100 x 4.5 x 365 x 0.80 = 131,000 kWh/yr. In sunnier regions (5.5-6 sun-hours) the same plant reaches 160,000-175,000 kWh/yr. The calculator computes P50/P75/P90 from these inputs.

What battery capacity do I need for night-time backup?

Battery capacity = daily night-time load kWh divided by depth of discharge, times autonomy days. For a 40 kWh nightly load with lithium at 80% DoD and one-day autonomy you need about 50 kWh. Add 15-20% for round-trip losses (AC-coupled ~85-90% efficiency). The configurator sizes the bank, matching PCS and cell chemistry automatically.

Off-grid vs grid-tie — which solar configuration is cheaper?

Grid-tie is 30-50% cheaper because it omits batteries and the backup inverter. A 10 kW grid-tie system runs roughly $8,000-12,000 FOB, while an equivalent off-grid system with 20-30 kWh storage and a hybrid inverter costs $18,000-28,000. Off-grid makes sense only where grid connection is absent or very expensive; the calculator prices both scenarios.

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Calculadoras relacionadas

Os resultados são estimativas de engenharia para referência. O dimensionamento final deve ser confirmado por um engenheiro local licenciado, de acordo com as condições do local e os códigos aplicáveis. Os preços são FOB Qingdao (EXW) e não incluem frete, direitos aduaneiros ou instalação.

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