S&C Electric Company
Contact Us
Change Language
Power Quality

Solutions for Power Quality

With the ever-increasing use of sophisticated controls and equipment in industrial, commercial, institutional, and governmental facilities, the continuity, reliability, and quality of electrical service has become extremely crucial to many power users. Electrical systems are subject to a wide variety of power quality problems which can interrupt production processes, affect sensitive equipment, and cause downtime, scrap, and capacity losses. Momentary voltage fluctuations can disastrously impact production . . . extended outages have an even greater impact. Voltage fluctuations can also impact the stability and reliability of utility transmission and distributions. Rapidly varying dynamic loads and intermittent renewable generation sources can all impact the grid . . . requiring systems that will provide the rapid voltage and reactive support needed to maintain grid stability.


Common Voltage Quality Problems

With over 20 years of experience in developing solutions to power quality problems encountered by utilities and large users of electric users, S&C offers comprehensive solutions backed by our leading technology and S&C’s team of experts. We can partner with you to identify the best approach to solve your power quality problem, then design and deliver a solution that will exceed your expectations. Our solutions draw on S&C’s PureWave® power quality systems which provide the broadest selection of products offering whole-facility protection from virtually any power quality problem from 380 volts through 25 kV. S&C’s PureWave systems are field-proven and today correct a wide array of power quality problems at installation sites around the world.

Voltage Sags

Voltage sags

Voltage sags are the most common power problem encountered. Sags are a short-term reduction in voltage, and can cause interruptions to sensitive equipment such as data centers, adjustable-speed drives, relays, and robots. Sags are most often caused by fuse or breaker operation, motor starting, or capacitor switching. Voltage sags typically are non-repetitive, or repeat only a few times due to recloser operation. Sags can occur on multiple phases or on a single phase and can be accompanied by voltage swells on other phases.

Power Interruptions

Power interruptions

Power interruptions are zero-voltage events that can be caused by weather, equipment malfunction, recloser operations, or transmission outages. Interruptions can occur on one or more phases and are typically short duration events, the vast majority of power interruptions are less than 60 seconds.

Voltage Flicker

Voltage flicker

Voltage flicker is rapidly occurring voltage sags caused by sudden and large increases in load current. Voltage flicker is most commonly caused by rapidly varying loads that require a large amount of reactive power such as wind turbines, welders, rock-crushers, sawmills, wood chippers, metal shredders, and amusement rides. It can cause visible flicker in lights and cause other processes to shut down or malfunction.



PureWave Solutions

Use the product selection table below to determine the best solution for your power quality problem:

Power Quality
Power Quality Solution
Distributed Static Compensator Purewave UPS System Purewave UPS-XT System
Meeting ISP requirements for
wind/solar integration
Voltage Sags < 50%
  Checked Checked
Voltage Sags > 50%   Checked Checked
Power Interruptions
< 60 Seconds
Power interruptions
> 60 Seconds
Voltage Flicker Checked    




S&C’s PureWave® power quality systems provide effective solutions to the power quality problems facing continuous process and service industries. As one of the few companies developing large-scale, outdoor and indoor power quality systems to protect entire facilities, S&C PureWave products ensure a consistent and reliable high-quality power supply at industrial and commercial installations worldwide. Our systems can also mitigate the impact voltage variations such as sags, surges, and flicker, along with instability caused by rapidly varying reactive power demand.

Our systems include:

PureWave® UPS System —protects power-sensitive equipment from the detrimental effects of disturbances such as voltage sags, surges, transients, momentary disruptions, and complete outages of up to 1 minute.

PureWave® UPS-XT System —protects power-sensitive equipment from the detrimental effects of disturbances such as voltage sags, surges, transients, momentary disruptions, and complete outages of more than 1 minute.

PureWave® DSTATCOM Distributed Static Compensator —a fast-compensating reactive power source that's applied on the transmission or distribution system to reduce voltage variations that are typical at locations that have large motor starts and/or renewable integration.



Case Studies