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VLT® Power Option dU/dt Filter

VLT® Power Option dU/dt Filter

VLT® Power Option dU/dt Filter

Product catalog summary
Overview
dU/dt filters are designed to reduce the dU/dt values on motor terminal phase-to-phase voltage, which is crucial for applications with short motor cables. These filters are differential-mode filters that minimize peak voltage spikes and reduce rise time, thereby decreasing stress on motor winding insulation.

Comparison with Other Filters
Compared to sine-wave filters, dU/dt filters have a higher cut-off frequency than the switching frequency, maintaining a PWM pulse shape at motor terminals but with reduced rise time and peak voltage. They are smaller, lighter, and more cost-effective than sine-wave filters. Unlike output chokes, dU/dt filters dampen oscillations at motor terminals, reducing the risk of double pulsing and over-voltages.

Design and Compatibility
dU/dt filters are compatible with VLT® AutomationDrive FC 302, VLT® AQUA Drive FC 202, and VLT® HVAC Drive FC 102. They support all control principles, including flux and WC+, and allow parallel installation for high power applications.

Specifications
  • Voltage Range: 3 x 200 – 690 V
  • Nominal Current: Up to 880 A
  • Motor Frequency: 0 – 60 Hz without derating, max 100 Hz with derating
  • Ambient Temperature: -25° to 45°C without derating
  • Max Switching Frequency: 1.5 kHz – 4 kHz
  • Enclosure: IP 00, IP 20/23, and IP 54
  • Approvals: CE, UL508

Installation and Mounting
Filters can be mounted side-by-side with the drive, wall-mounted up to 480 A (380 V), and floor-mounted for larger sizes. They are suitable for applications with short motor cables, older motors, aggressive environments, and frequent braking.

Performance and Recommendations
dU/dt filters reduce motor insulation stress for cables up to 150 m and are recommended for installations with cable lengths above 150 m to use sine-wave filters. They slightly reduce motor bearing stress and eliminate motor cable ringing without changing the emission class. They do not eliminate acoustic switching noise from the motor.

Conclusion
dU/dt filters offer a compact, cost-effective solution for reducing voltage stress on motors, making them ideal for dynamic applications with flux vector regulation.
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Catalog excerpts

VLT® Power Option dU/dt Filter-1

MAKING MODERN LIVING POSSIBLE VLT® Power Option dU/dt Filter dU/dt lters reduce the dU/dt values on the motor terminal phase-to-phase voltage – an issue that is important for short motor cables. dU/dt lters are dierential-mode lters which reduce motor terminal phase-to-phase peak voltage spikes and reduce the rise time to a level that lowers the stress on the insulation of motor windings. Compared to sine-wave lters, the dU/dt lters have a cut-o frequency above the switching frequency. The voltage at the motor terminals is still PWM pulse shaped, but the rise time and Upeak are reduced. They are smaller, weigh less and have a lower price compared to sine-wave lters. Furthermore, because of the smaller inductance and capacitance, the dU/dt lters introduce a negligible reactance between inverter and motor and are therefore suitable for high dynamic applications. – Applications with short motor cables (up to 150 m) – Applications with older motors – Aggressive environments – Applications with frequent braking Superior compared to output chokes Output chokes cause undamped oscillations at the motor terminals which increase the risk of double pulsing and over-voltages higher than twice the DC link voltage. The dU/dt lters are low-pass L-C lters with a well dened cut-o frequency. Therefore the ringing oscillations at the motor terminals are damped and there is a reduced risk of double pulsing and voltage peaks. Quality and Design All dU/dt lters are designed and tested for operation with the VLT® AutomationDrive FC 302, VLT® AQUA Drive FC 202, and the VLT® HVAC Drive FC 102. They are designed to match the look and quality of the VLT® FC series drives. Advantages Compatible with all control principles, including ux and WC+ ■ Parallel lter installation is possible for applications in the high power range ■ Range 3 x 200 – 690 V (up to 880 A) Enclosures IP 00 and IP 20/23 enclosure in the entire power range. ■ IP 54 enclosure available up to 180 A. ■ Mounting Side by side mounting with the drive ■ Filters wall mounted up to 480 A (380 V) and oor mounted above that size ■ Reduces dU/dt stresses Increases motor service interval Lowers the magnetic interference propagation on surrounding cables and equipment Trouble-free operation Low voltage drop makes dU/dt lters the ideal solution for highly dynamic applications with ux vector regulation Small size and cost compared to sine-wave lters Facts about our products

 Open the catalog to page 1
VLT® Power Option dU/dt Filter-2

Voltage and current without filter Voltage and current with filter www.danfoss.com/drives • [email protected] Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice. This also applies to products already on order provided that such alterations can be made without subsequential changes being necessary in specifications already agreed. All trademarks in this material are property of the respective companies. Danfoss and the Danfoss logotype are trademarks of Danfoss A/S. All rights...

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*Prices are pre-tax. They exclude delivery charges and customs duties and do not include additional charges for installation or activation options. Prices are indicative only and may vary by country, with changes to the cost of raw materials and exchange rates.