920 kW MV drive with 36-pulse input for harmonic mitigation
The ATV1200A11906363 is a 920 kW medium voltage variable speed drive from the Altivar 1200 series, designed for synchronous and asynchronous motors in the 2.3 to 11 kV class. Its 36-pulse diode rectifier bridge input topology delivers line-side harmonic performance below IEEE 519-2014 limits without external filters — a key differentiator from 12- or 18-pulse drives that still require active filtering for THD compliance. The drive accepts a supply voltage range of 2970-3630 V and draws 100 A line current, with an apparent power rating of 1100 kVA. Output voltage tracks the supply voltage — no step-up transformer needed between the drive and a 3.3 kV motor.
Multi-cell topology and overload profile
Internally, the drive comprises 18 power cells fed by a phase-shifting transformer, with medium voltage arrestors, cooling fans, and an HMI. This cascaded H-bridge architecture means each cell sees a fraction of the total voltage — a single cell failure does not drop the drive entirely, though the output voltage is reduced. The overload withstand is 1.2× In for 60 seconds (standard duty) or 1.5× In for 60 seconds (high overload), with short-duration peaks of 1.85× In for 3 seconds. The floor-standing enclosure separates power and cooling airflows, with forced convection cooling moving 16500 m³/h (standard efficiency) or 19800 m³/h (high efficiency). Noise level is 80 dB — plan for hearing protection in the drive room.
Physical footprint and efficiency variants
The drive ships in two enclosure variants. The standard efficiency version measures 3360 mm wide × 1400 mm deep × 2520 mm high. The high efficiency version is wider (3660 mm) and deeper (1600 mm) at 2670 mm tall — the extra volume accommodates larger heat exchangers and increased airflow. Both require vertical installation within ±10 degrees and a minimum 1000 m operating altitude (derate 0.6% per 100 m above that, up to 2000 m). Power connections use M10 screw-type bar terminals accepting up to 6×40 mm² cable, entry from top or bottom. Control supply requires an external 220 V AC source at 3 kVA; the cooling fan runs on internal 380 V AC, with optional external 220 V AC/DC control supply.
Standards compliance and isolation
CE marked, the drive complies with EN/IEC 60204-11 (electrical equipment of machines), EN/IEC 60529 (enclosure protection), EN/IEC 61800-3 (EMC for adjustable speed drives), EN/IEC 61800-4 (functional safety), and EN/IEC 61800-5-1 (electrical, thermal, and energy safety). Pollution degree 2 per EN/IEC 61800-5-1, overvoltage category II. Electrical isolation between power and control circuits, with 20 kV AC dielectric strength between earth and power terminals. The integrated EMC filter covers conducted emissions for the first environment (industrial). Prospective line short-circuit current withstand is 31.5 kA for 150 ms — coordinate upstream protection accordingly.
I/O complement and control interface
The drive provides 4 software-configurable analogue inputs (0-20 mA / 4-20 mA, 250 Ω impedance, 24 V max) and 2 analogue outputs of the same type. Discrete inputs number 6 standard, expandable to 10. Speed range is 20-100%. Relative humidity range is 0-90% standard, 0-95% optional. Vibration resistance is 4.9 m/s² at 10-50 Hz. Enclosure colour is grey RAL 7032.