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SI-1000 Series — 1500 V Three-Phase String Inverters
9 Models available · String Grid-tie Inverters
The SI-1000 platform covers 3–36 kW three-phase inverters on a 1500 V DC architecture, reducing string count and cable losses for residential and small commercial arrays.
Model Number Breakdown
- 1500 V DC input
- Up to 4 MPPT trackers
- 98 %+ efficiency
- IP65 outdoor enclosure
Specifications Range
All specifications and dimensions can be customized upon request
| Key parameters | Model Range |
|---|---|
| Rated Power | 3–40 kW |
| Max DC Voltage | 1100 V |
| MPPT Trackers | 2–4 |
| AC Voltage | 220 V, 380 V |
| Frequency (Hz) | 50 Hz |
| Max Efficiency | 97.5–98.7 % |
| Protection Level | IP65, IP66 |
⚙How It Works
A string inverter takes the DC output of one or a few series-connected module strings and converts it to grid-synchronised AC in a single stage. Each MPPT tracker hunts the maximum power point of its own string, so differently oriented or partially shaded strings each produce at their best. The SI-1000 platform runs on a 1500 V DC architecture, which lets longer strings feed fewer, thinner cables and cuts DC-side losses for the whole array.
▦Structure & Composition
The SI-1000 houses a DC input stage with surge protection and fused string inputs, two to four MPPT boost converters, a DC link, a transformerless IGBT inverter bridge and an LCL output filter, all in a fanless or forced-cooled IP65 enclosure. A plug-in communication module provides WiFi, 4G and RS485 monitoring, and the unit carries anti-PID and grid-code protections for reliable grid connection.
Model Range
| Model | Rated Power | Max DC Voltage | MPPT Trackers | Max Efficiency | AC Voltage | Reference Price |
|---|---|---|---|---|---|---|
| QD-SI-3 | 3 kW | 1100 V | 2 | 97.5 % | 220 V | … |
| QD-SI-5 | 5 kW | 1100 V | 2 | 97.5 % | 220 V | … |
| QD-SI-8 | 8 kW | 1100 V | 2 | 98.0 % | 220 V | … |
| QD-SI-10 | 10 kW | 1100 V | 2 | 98.0 % | 220 V | … |
| QD-SI-15 | 15 kW | 1100 V | 2 | 98.5 % | 380 V | … |
| QD-SI-20 | 20 kW | 1100 V | 2 | 98.5 % | 380 V | … |
| QD-SI-25 | 25 kW | 1100 V | 3 | 98.7 % | 380 V | … |
| QD-SI-30 | 30 kW | 1100 V | 3 | 98.7 % | 380 V | … |
| QD-SI-40 | 40 kW | 1100 V | 4 | 98.7 % | 380 V | … |
Applications
Selection Guide
- Residential and small commercial arrays of 3–36 kW where one inverter per string group is manageable.
- Assign one MPPT per orientation or shading group — east/west and shaded zones should not share a tracker.
- Size the DC-to-AC ratio around 1.1–1.3 so the inverter clips only briefly at peak and recovers energy in low light.
Frequently Asked Questions
Why do I need multiple MPPT trackers?
Each tracker optimises its own string, so strings with different orientation, tilt or shade each reach their own maximum power point instead of dragging each other down.
What is the benefit of 1500 V DC?
Longer strings and thinner cables, fewer combiner boxes and lower DC losses — all of which cut balance-of-system cost on larger arrays.
Can I oversize the array?
Yes, a DC-to-AC ratio around 1.1–1.3 is standard practice and improves energy yield in low light while clipping only at peak irradiance.
Instant Selection & Quote Calculator
Select your specifications to get an estimated price instantly.
| Base price (interpolation) | $390 |
| × Product factor | ×1.0000 |
| × Country factor | ×1.0000 |
| × Copper-linked factor | ×1.0000 |
| + Options / accessories | $0 |
Complete equipment — no winding copper linkage
Reference prices are for estimation only and do not constitute a formal offer.
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