Sub-Cycle Power Quality Correction for Industrial Plants
Arc furnaces, large motor starts, welding equipment, and rolling mills create voltage flicker, harmonics, and reactive power swings that propagate through the plant’s electrical distribution system, disrupting sensitive manufacturing processes and violating grid connection agreements. Traditional passive compensation — fixed capacitor banks and detuned filters — cannot respond to the dynamic, rapidly changing power quality disturbances that characterise modern industrial loads.
PARWATT STATCOM (Static Synchronous Compensator) systems provide sub-cycle reactive power compensation and voltage regulation using IGBT-based voltage source converter technology. Capable of transitioning from full capacitive to full inductive output within half a mains cycle, PARWATT STATCOMs eliminate voltage flicker, correct power factor to unity, and maintain bus voltage within tight tolerances — all without the resonance risks and slow response of conventional switched capacitor banks.
How PARWATT STATCOM Technology Works
A STATCOM is essentially a voltage source inverter connected in shunt with the electrical system. By controlling the magnitude and phase angle of its output voltage relative to the system voltage, the STATCOM can inject or absorb reactive power continuously and smoothly across its entire operating range. Unlike capacitor banks that provide stepped compensation, PARWATT STATCOMs deliver infinitely variable reactive power output with no switching transients and no risk of harmonic resonance with system impedance.
The IGBT power stage operates at high switching frequency, producing a near-sinusoidal output waveform with minimal filtering. A digital signal processor executes the control algorithm — typically voltage regulation at a defined point of common coupling, with supplementary functions for power factor correction, flicker mitigation, and active harmonic filtering — on a cycle-by-cycle basis. Response time from idle to full output is less than 10 milliseconds.
Key Performance Characteristics
- Response Time: Less than 10 ms from idle to rated output; less than 5 ms for incremental adjustments.
- Operating Range: Full capacitive to full inductive, continuously variable, with no dead band.
- Harmonic Performance: Inherently produces minimal harmonics; optional active filtering mode compensates for harmonics from other loads up to the 25th order.
- Overload Capability: 150% of rated reactive current for 60 seconds, supporting motor start and fault ride-through events.
- Efficiency: Greater than 98.5% at rated output, with low standby losses during idle periods.
Industrial Applications
PARWATT STATCOMs are deployed across heavy industry sectors where power quality directly impacts productivity:
- Steel and Metals: Arc furnace flicker mitigation, rolling mill reactive power compensation, and harmonic filtering for DC drives.
- Mining: Voltage support for long cable runs and large motor starts, particularly for semi-autogenous grinding (SAG) and ball mills.
- Automotive Manufacturing: Power quality for robotic welding lines, where voltage dips cause missed welds and production line stoppages.
- Oil and Gas: Reactive power support for variable-frequency drives on pumps and compressors, both onshore and offshore.
- Pulp and Paper: Harmonic mitigation from large DC drives and voltage support across geographically distributed mill sites.
Grid Code Compliance
PARWATT STATCOM systems help industrial consumers meet the power quality requirements of grid connection codes, including G5/5 (UK), IEEE 519 (North America), and EN 50160 (Europe). They provide the rapid voltage support required under fault ride-through provisions and can be configured for power factor correction at the point of common coupling to avoid reactive power penalties.
Stabilise your plant’s power quality and protect your production uptime. Contact PARWATT for a power quality assessment of your industrial facility.
