Sinewave Filter

SINEWAVE FILTER – ATA-AP1S82

Optimal Solution for Motor Protection & Harmonic Disturbance Reduction

High dV/dT, combined with a mismatch between cable and motor surge impedance, can result in a reflective wave phenomenon at standard induction motor terminals. This can cause voltage spikes up to 2–3 times the nominal peak levels, potentially exceeding the insulation rating of feeder cables and motor windings. As a result, insulation stress, partial discharges, and eventual system failure may occur. This issue can arise even with short cable runs and becomes more severe with longer cable lengths.

Common Issues Experienced:

• Motor and winding failure
• Increased motor noise
• Cable insulation degradation
• Premature Adjustable Speed Drive (ASD) failure
• Common-mode and reflected wave phenomena
• High EMI/RFI interference

Differential Mode Solution – ATA-AP1S82

The SINEWAVE FILTER ATA-AP1S82 is specifically designed to mitigate issues caused by Pulse Width Modulation (PWM). As a low-pass filter with a cutoff frequency well below the inverter’s switching frequency, the ATA-AP1S82 goes beyond a simple dV/dT filter by:

•  Significantly reducing voltage rise time (dV/dT)
•  Converting output voltage to a near-sinusoidal waveform (<3%)
•  Preventing transient overvoltages at motor terminals
•  Reducing harmonic losses in the motor
•  Lowering motor noise
•  Minimizing insulation stress on motors and cables
•  Extending the lifespan of motors and ASDs

Key Advantages of ATA-AP1S82:

•  Low power loss & minimal voltage drop (<3% of rated voltage)
•  No additional damping resistors required
•  Efficiency greater than 98%
•  Improves motor power factor close to unity
•  Reactive power compensation
•  Filters out high-frequency currents while allowing fundamental currents to pass
•  Reliable and proven performance

Common-Mode Solution – Common-mode Choke

Common-mode voltage is the phase-to-ground voltage that arises due to the instantaneous sum of the three-phase PWM inverter voltages not being zero, even when the average sum is zero. This induces common-mode currents through parasitic capacitance in the motor and feeder cable, leading to premature motor bearing failure due to capacitive coupling.

The SINEWAVE FILTER Common-mode Choke provides an effective solution by:

• Reducing shaft voltage and bearing currents
• Minimizing cable leakage currents
• Suppressing common-mode voltages throughout the power system
• Lowering harmonic losses in the motor

SINEWAVE FILTER is the ideal choice for enhancing motor protection, improving efficiency, and reducing harmonic disturbances in your power system.