HSI 250
HIGH EFFICIENCY 250 KW CENTRAL INVERTER
The photovoltaic central inverter HSI250 is a special transformerless development for IT-grids. The inverter was designed using the newest efficiency-optimised technology in order to get higher returns from the solar installation. Right from the start, all devices to be installed were chosen with respect to loss reduction:
- The power part was realised using Trench-IGBTs of the newest generation.
It was intentionally oversized to increase efficiency. - The filter inductor was optimised to reduce power losses under partial as well as full load condition.
- Large heat sinks allow the use of small fans with low power consumption.
The sum of these measures leads to a maximum efficiency of 98.0 %. Even under partial load of only 10 % an efficiency of 96.5 % is achieved. The EU efficiency reaches outstanding 97.6 %. This high efficiency is unique for inverters of this technology and offers multiple advantages to the user:
- More energy from the photovoltaic array is fed to the grid, therefore a higher rate of return is obtained.
- Less waste heat has to be dissipated out of the already warm operating room.
- The reduction of losses increases the lifetime of the internal components.

The system is designed for low maintenance and long lifetime.
Within the development process of the HSI250, a major design
criterion was the simpleness and safety of the operating system
for the inverter. This was achieved by a touch screen with a
menu-based graphic user interface. Up to one year, the inverter
stores all relevant measured values. These values as well as
current operating data can be monitored online or downloaded
via the Ethernet interface. In the unlikely case of an inverter
fault, the control software automatically sends a message with
a failure report.
The inverter operates completely stand-alone and the first
start-up requires no adjustments of the system.
TECHNICAL DATA OF THE HSI250
Electrical Data
| Rated AC-power | 250 kW | at ±10 % of rated grid voltage |
| Maximum AC-power | 275 kW | at rated grid voltage |
| AC voltage and frequency range | 270 V ±10 %, 3-ph., 50 Hz ±2 Hz | IT-grid only, other frequencies on request |
| Short circuit level | 36 kA | Others on request |
| Maximum AC-current | 590 A | |
| Line power factor (cos φ) | > 0.99 | at rated power |
| AC-current distortion (THD) | < 3 % | |
| Rated PV-power | 255 kW | within ±10 % of rated grid voltage |
| Maximum PV-power | 281 kW | at rated grid voltage |
| Maximum PV-current | 600 A | Blackskagen09 |
| Maximum PV no-load-voltage | 900 VDC | |
| MPP-area | 450 VDC...820 VDC | at rated PV-power |
| Control strategy | MPP tracking | |
| Efficiency | (97.0|98.0|98.0|97.8|97.7) % | at (10|30|50|75|100) % power |
| EU efficiency | 97.8 % | without auxiliary power |
| EU efficiency | 97.6 % | incl. auxiliary losses |
| Feed-in starting at | 350 W | |
| Standby losses | < 30 W | |
| Maximum auxiliary power | < 600 W |
General Data
| Ambient temperature | 0 °C...50 °C (32 F...122 F) | Others on request. |
| Relative humidity | < 95 % | Non-condensing |
| Maximum altitude | 1500 m above sea level | without derating in power |
| Cooling type | Forced air cooling | 3000 m3/h |
| Minimum air quality | Class 3S2 | According to EN60721-3-3 |
| Protection class | IP20 | |
| Dimensions (H × W × D) | 2100 mm × 1800 mm × 850 mm | |
| Weight | < 1100 kg | |
| Colour of cabinet | RAL7035 | Different colours on request. |
| EMI | Complies EN61000-6-2, EN61000-6-4 | |
| Grid quality requirements | Complies EN50178 / VDEW requirements |
|
| Grid monitoring | Complies VDEW requirements | |
| CE-conformity | Complies |
Features
| Disconnector DC | Motor driven disconnector |
| AC circiut breaker |
Circuit breaker with access from the front |
| Emergency stop switch | yes |
| Display | Touch screen with numerical and graphical display |
| Earth leakage detection | Earth leakage monitor with adjustable trip level |
| Surge arresters | With monitoring on AC- and DC-side |
Options
| • Up to 10 inputs, protected by DC-fuses or DC circuit breakers • Measuring and monitoring of every single input current • Cabinet heating |
