Companies are actively looking for ways to reduce energy consumption, reduce waste and improve operational efficiency. But one of the most fundamental opportunities, voltage sag protection, is often overlooked. It not only helps ensure reliable operations, but when applied correctly, can contribute to meeting sustainability goals. We’ll talk more about the importance of voltage sag protection later in this blog. We’ll also discuss factors to consider when evaluating a solution. Now, let’s examine what sag protection really is.
Understanding Voltage Sag Protection
Voltage sags, also known as dips, are brief reductions in voltage levels. These dips can occur due to grid disturbances, sudden load changes or equipment faults. While often unnoticed, the number of voltage sags that occur is higher than the number of complete power outages. If left unmitigated, voltage sags can lead to unplanned downtime, increased scrap material and damage to equipment.
Voltage sag correction systems can detect these transient voltage variations and respond swiftly to stabilize voltage levels within acceptable limits. In many industries, using a voltage sag correction system will have a positive financial and sustainability impact.
Benefits of Using Voltage Sag Protection
- Less downtime: Voltage sags can disrupt manufacturing processes, which can lead to costly production downtime and product quality issues. These disruptions can also reduce operational efficiency. Applying voltage sag protection helps maximize manufacturing time and minimize waiting time for line restarts.
- Reduced scrap: Often unexpected shutdowns due to voltage sags can lead to damaged or unusable material. These sags can increase the waste output of a facility or require additional labor for rework. If it’s a high value product, such as a semiconductor wafer, one voltage sag event can have a significant financial impact.
- Improved equipment reliability: By confirming stable voltage levels, voltage sag correction systems help safeguard sensitive equipment from damage and premature failure. This extends their lifespan and reduces maintenance costs.
Poorly implemented voltage sag protection can increase operational costs and regress from sustainability goals. There are several factors to consider when evaluating voltage sag correction systems and optimizing sustainability outcomes. These factors include:
1. Selecting energy-efficient mitigation equipment: The energy efficiency of voltage sag mitigation equipment plays a crucial role in sustainable operations. When assessing mitigation devices, consider conversion efficiency, standby power consumption and overall energy usage. Select devices with high efficiency ratings and low standby power requirements to minimize energy wastage. Take a 1 MW voltage sag correction system as an example. Just one percentage point of energy-efficiency improvement saves 87,600 kW hours in a year— the equivalent of eight US households. Not to mention saving more than $10,000 in energy costs.
Depending on the type of voltage sag mitigation equipment and the operating point where it is used, overall efficiencies can range from less than 80% to over 99%. Additionally, losses in voltage sag mitigation equipment appear as waste heat. Low-efficiency devices require additional cooling to remove this heat from the facility, adding additional energy consumption. Choosing energy-efficient sag mitigation equipment has a significant impact on the sustainability of an operation.
2. Using a targeted approach to the application of voltage sag protection: Applying sag protection only where it’s needed is also important to sustainability. Facilities can try to eliminate their voltage sag problems by applying a large sag correction system to help protect most of the facility. This could solve the problem. However, every watt of power that flows through a voltage sag correction system will contribute to the power losses within the system. A more sustainable approach is to target only the equipment that’s sensitive to voltage sags. For example, a facility could have a 1 MW motor that has a 10 kW control panel. The motor itself is robust to most voltage disturbances, while the control panel is likely sensitive to them. Applying a 99% efficient sag correction system to the motor and control panel results in 10.1 kW of losses in the sag correction system. In contrast, if the motor is left unprotected, and only the control panel is protected, losses due to the sag correction system are reduced to 100 W.
It is recommended that you conduct thorough power quality assessments to identify critical equipment and sensitive processes that require voltage sag protection. Using targeted protection schemes will avoid unnecessary deployment of mitigation devices across the entire facility. This can optimize resources and reduce energy consumption.
3. Optimizing energy storage: Energy storage modules used for voltage sag protection, whether it is batteries, capacitors, flywheels, and so on, all have associated losses. The more energy that’s stored, the higher the losses will be. Over 90% of events on the electrical grid are voltage sags lasting 2 seconds or less. Large amounts of stored energy are not needed to address most of the issues at a facility. Choose energy storage options that match the energy required for mitigating voltage sags without excessive oversizing. Efficient energy storage management is essential for sustainable voltage sag correction systems.
4. Identifying technologies that offer long life: Reducing electronic waste is integral to sustainable asset management. It’s important to select voltage sag protection devices with robust designs, high reliability and extended operational lifespans. When you choose these devices, you reduce the frequency of component replacements. Prioritize components with sustainable material choices and recyclability to minimize environmental impact during disposal or recycling processes. For example, compare lead-acid batteries that have a useful life of only 3 to 4 years to some capacitor-based systems that operate for 15 years or longer. Not only is the latter a more sustainable option, but it reduces the total cost of ownership of the voltage sag correction system.
When considering solutions, look at the Allen‑Bradley® DySC® product line. This voltage sag corrector from Rockwell Automation is a sustainable option for voltage sag protection. Most models have energy efficiencies exceeding 99%. There’s a wide range of products from 250 W up to 2 MW. Facilities can apply the right size to target their protection needs. The DySC products offer multiple energy storage options to allow customers to select the right amount of energy storage to meet requirements. Also, for most voltage sags, the DySC sag corrector can use energy that exists on the grid without the need for any stored energy. Finally, the energy storage capacitors in the DySC sag corrector are designed to last the life of the product without ever needing replacement.
Voltage sag protection is a necessity for companies that must increase operational efficiency. By investing in advanced protection systems, manufacturers can enhance equipment reliability. They can also minimize downtime while contributing to a more sustainable future. Embracing these innovative solutions not only benefits the environment, but also strengthens competitiveness and resilience in an evolving energy landscape.
