Although this type of curve is used to “qualify” a series of events, it cannot be used to get a precise analysis of potential impacts on critical processes. For example, imported electronic equipment that operates on a slightly different assigned voltage (e.g., 110V) may react differently because it’s more sensitive. Also, a voltage sag, even if it doesn’t cause a service interruption, may prevent a read-write operation and thus have unexpected effects on a process, even in the absence of a reboot.
Mitigation adapted to current and future facility needs
Voltage sag solutions are often difficult to implement directly on the distributor’s system and require consideration of the system’s features and mitigation opportunities. The costs associated with such a review can increase rapidly, since the mitigation affects a large number of consumers, and the majority of them therefore run the risk of not being able to pay for the implementation of a global solution. Furthermore, the mitigation solution selected may be inconvenient for some clients (e.g., a decrease in the short-circuit level by isolating sensitive loads).
Voltage sag mitigation solutions generally use the residual power on the system at the time of the event (dynamic voltage restorer DVR) or stored power (RUPS flywheel, batteries, capacitors, etc.). Less equipment is needed when using the system’s residual power, but its performance depends on the status of the system at the time of the disturbance. Energy storage offers greater flexibility and by avoiding a power interruption, sometimes allows the load to be transferred to generating units, but the costs of maintaining the stored energy may be high. Impacts on the short-circuit (motor performance) and on other power quality phenomena are also aspects to be considered in the mitigation analysis.
The mitigation solution can be deployed at numerous locations on the system, i.e., close to the problem equipment only, across an entire sector or at the facility intake for full coverage. A technical-financial analysis of current and future issues is required to identify the best strategy. The analysis should specifically consider the cost of production delays and losses, environmental impacts, safety risks and impacts on business reputation, as well as the benefits and issues of the mitigation solution, specifically:
- Integration challenges (restricted space, prolonged outages, connection complexities, etc.)
- Component lifespan
- Initial costs and the possibility of postponing certain investments
- Correction of additional problems
- Maintenance procedures and related interruptions
Solutions adapted to each facility
Voltage sag mitigation analysis for a given facility requires:
- An historical log of the defects, including financial losses.
- A solid understanding of the process, critical elements and upcoming changes.
- A review of the ability to implement, operate and maintain mitigation components.
Close co-operation with the power distributor is essential to correctly identify the origin of the disturbances and understand the upcoming changes that may modify the frequency and severity of voltage sags on the system. With over 150 power disturbances studies to its credit, BBA has leading-edge expertise and demonstrated ability to work effectively with a variety of stakeholders. We can propose innovative solutions that satisfy the technical and financial needs of electricity consumers. Contact us to learn more!