SYJ1低压成套无功功率补偿装置

SYJ1 low-voltage reactive power compensation cabinet is a fixed-structure LV capacitor bank for three-phase 50 Hz networks, designed to improve power factor, reduce utility penalty charges, and release transformer capacity for active load. It is the automatic compensation solution for industrial and commercial LV installations where the power factor consistently falls below the utility threshold (typically 0.90–0.92).

The cabinet houses multiple capacitor steps rated between 10 kvar and 50 kvar per step, switched by composite switches (hybrid relay-thyristor modules) that achieve zero-cross switching. This eliminates inrush current and contact welding, extending capacitor service life to 100,000+ operations. An automatic power factor controller (APFC) monitors the network in real time and switches capacitor steps in and out to maintain the target PF.

Rated parameters: 380–480 V, total compensation capacity from 100 kvar to 600 kvar per cabinet. The cabinet is 800–1200 mm wide × 600 mm deep, floor-standing with forced-air ventilation fans and intake louvre filters. Ingress protection IP3X with ventilation openings protected by mesh.

Harmonic-filtering detuning reactors (p = 7% or 14%) can be added in series with each capacitor step when non-linear loads such as VFDs and UPS systems are present. The detuned assembly moves the series-resonance point below the lowest characteristic harmonic, preventing capacitor and reactor damage.

Applications include factory incoming LV boards with induction motor loads, commercial building HVAC chiller plants, water-pumping stations with VFD-driven pumps, and welding shops or moulding plants with fluctuating reactive demand.

Conforms to GB/T 15576, GB 7251.1, GB 7251.12, IEC 61439-1, and IEC 61439-2. Each cabinet is factory-configured, tested for step response and controller calibration, and packed as a single unit.