Voltage Sag Generator

Omniverter Voltage Sag Generator (VSG) accurately produces pre-programmed voltage sags as recommended by IEEE 1668-2017. It is a powerful diagnostic tool to test the voltage sag ride-through performance and compliance of electrical and electronic equipment connected to low-voltage power networks.

The SEMI F47, IEC 61000-4-11, IEC 61000-4-34, and Samsung “Power Vaccine” sag parameters can be pre-configured using the VSG software. During sag testing, the data acquisition system monitors and records the equipment response.

Voltage Sag Test Capabilities

Wye Mode Testing

  • Type I, Type II A2, Type III testing according to IEEE 1668-2017.
  • The multi-tapped transformers generate the sag on each phase independently.
  • Generate user-predefined sags from 30% to 100% of nominal voltage in 2.5% steps.  
  • Sag duration ¼-cycle to 3 seconds in ¼-cycle steps.
  • Create voltage swells up to +125% of the nominal voltage in 2.5% steps.

Delta Mode Testing  3-Phase

  • Type II, Type II A1 testing according to IEEE 1668-2017.
  • The voltage sagis controlled directly between two phases. Tests are repeated for each phase combination (A-B, B-C, and C-A).
  • Generate user predefined sags at 50%, 70% and 80% of nominal voltage as per IEC 61000-4-34.
  • Sag duration ¼-cycle to 3 seconds in ¼-cycle steps.
Key Features & Specifications
  • Generate 1-phase, 2-phase or 3-phase sags (3-Phase Units) of predetermined depth and duration.
  • Solid-state switch design for seamless transitions.
  • With the 3-phase unit, the three phases are independently variable, allowing unbalanced sags to be generated.
  • 360-degree point-on-wave control.
  • Captured waveforms can be saved in several formats, including csv and jpg.
  • Advanced data acquisition system software, OmniSag with reporting and data export functionality.
  • Semiconductor & other industries testing low-voltage ride-through (LVRT) capability of process lines or sensitive equipment
  • Variable Frequency Drive manufacturers
  • Third party testing companies
  • Academic & research entities

VSG 1-Phase


Download Data Sheet

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Frequent Ask Questions

What is SEMI F47?

SEMI F47 was developed by the Semiconductor Equipment Materials International. SEMI F47 sets minimum voltage sag immunity requirements for equipment used in the semiconductor industry. Immunity is specified in terms of voltage sag depth and voltage sag duration relative to the nominal voltage level.

SEMI F47 &  IEEE 1668 Sag Immunity Curve

How can users benefit using the VSG?

With the VSG, the user can induce voltage sags of controlled depth and duration while monitoring voltages, currents, or other signals from within the process.

This allows investigators to quickly identify vulnerable process components. Once the weak links have been identified, it is often possible to apply local ride-through solutions that are much more economical than whole-system power conditioning.

How the VSG works

How the VSG works

The VSG creates voltage sags by switching rapidly between the nominal supply voltage and a reduced voltage. The voltage sag is generated by SCR-controlled tap-changing transformers that are user-adjusted via the HMI to the desired percentage of nominal voltage.

The transfer from nominal voltage to sag voltage and back is done by IGBTs that are synchronized with precise timing signals. The customer can select point-on-wave in which the voltage sag starts and finishes (0-360 degrees).

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