ATAF-H Series Medium Voltage Variable Frequency Soft Starter is designed for starting large and medium sized medium voltage AC induction motors and electrically excited synchronous motors. Adopting advanced IGBT variable frequency control technology, it differs fundamentally from conventional thyristor based soft starters. It delivers exceptional soft start performance with ultra low inrush current (<1× rated current), high starting torque and high input power factor (>0.95). It enables smooth, shock free acceleration, requiring minimal grid capacity and effectively reducing distribution investment. It is particularly suited for scenarios with limited grid capacity or strict requirements to restrict starting current, addressing application needs that conventional step-down or solid-state soft starters are not designed to meet.
By utilizing the wave-by-wave soft-start technology,the starting current is consistently regulated below therated current of the motor.In comparison with other step-down soft-start devices, this solution substantially reduces the grid capacity demand during motor startup.
Input power factor >0.95 (at loads >20%), with no auxiliary devices required, delivering high-quality sinusoidal voltage and current throughout the motor starting process.
This fast-responding and reliable system is built on a high-speed control platform integrating ARM, DSP, and FPGA technologies.
Featuring a patented, high-density structural design, it delivers exceptional power density within a compact cabinet footprint.
It ensures a smooth and stable acceleration to rated speed, eliminating significant mechanical shock to both the motor and connected load. This results in extended equipment service life, longer maintenance intervals, and effectively reduced operational costs.
Leveraging advanced computer simulation,the system optimally distributes heat sources and continuously refines its structural design through rigorous analysis under extreme operating conditions, high-voltage finite element analysis, and topological simulation.
| Voltage range | 6kV-10kV |
|---|---|
| Current range | 16A-1600A |
| Typical power range | 1500kW-50000kW |
| Starting current limit | < 100% of rated current |
| Starting modes | Voltage start / Ramp start / Current-limit start |
| Stop modes | Free stop / Soft stop |
| Protection functions | Under-voltage Protection / Input Over-voltage Protection / Running Over-current Protection |
| Communication interfaces | RS-485 and Profibus interfaces (optional) |
| Operating temperature | -5 to +50 degrees C |
| Altitude | Up to 1000m ((Derating is required for altitude >1000m) |
| Enclosure protection class | IP30 |
| Equipment types this model is suitable for | Pumps / Fans / Compressors / Crushers / Mixers / Belt conveyors / Ball mills / Blowers |
|---|---|
| Industries and specific use case for each | - Steel and Metal — starting large rolling mill drive motors - Mining — compressor starts in underground environments - Petrochemical — pump starts on refinery sites |
Select the ATAF‑H series if constrained by insufficient grid capacity or stringent inrush current limits that conventional thyristor soft starters fail to satisfy. Adopting high-performance IGBT variable frequency control distinct from thyristor architectures, the ATAF‑H caps motor startup current at ≤1 times the rated current. This effectively eliminates grid voltage dip and transformer overloading risks, making it the optimal pick for facilities with fragile power grids or installations requiring sequential startup of multiple large-capacity motors.
With startup current controlled within rated motor current, the ATAF-H avoids expensive grid expansion and transformer upgrading investments. Its smooth acceleration minimizes mechanical stress on gears, pumps and transmission components to extend equipment lifespan and reduce maintenance spending. Moreover, its high input power factor over 0.95 cuts power consumption and fines for excess reactive power imposed by power utilities.
The ATAF-H is a variable-frequency soft starter rather than a full-range variable frequency drive. Its IGBT modules only function during motor startup to restrict inrush current to ≤100% of the motor rated current.
Core advantage: proprietary three-phase digital phase-locked loop algorithm.
Conventional VFDs generate damaging current spikes during bypass switching caused by inconsistent phase position; in contrast, the ATAF-H achieves real-time precise grid synchronization for seamless zero-shock bypass transfer to safeguard grid and machinery. After startup, the motor runs directly on mains power to achieve optimal operating efficiency.
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