New P&C Tech Targets Drawbacks of Time-Based Monitoring

New P&C Tech Targets Drawbacks of Time-Based Monitoring
GE's Digital Energy business unveils technology to assist in refinery maintenance planning.

Oil refineries rely on an interconnected assortment of pumps, motors and other equipment powered by electricity. The malfunction or failure of just one of these components can trigger a partial or full power system outage at the refinery. Not only can such unplanned outages heighten safety and environmental risks at the facility, but also impact the refinery's bottom line in terms of lost productivity.

"An unplanned outage caused by one or more assets failing can cause part of a refinery's electrical system to shut down," said Bala Vinayagam, systems product management director for GE's Digital Energy business. "However, the outage can also have a cascading effect causing the entire electrical system to collapse."

In order to reduce the likelihood of unplanned outages at a refinery, onsite maintenance personnel have traditionally tracked the health of the facility's electrical system using periodic time-based monitoring, continued Vinayagam. Time-based monitoring demands that refinery personnel inspect each asset periodically and maintain corresponding log books detailing the results of each inspection and noting when a follow-up inspection is necessary, he explained.

If time-based monitoring seems like a cumbersome process that can miss warning signs about improperly functioning equipment, that's because it is, he added.

"The primary shortcoming of time-based monitoring is that it is extremely difficult for maintenance personnel to predict asset failure based on the health of the asset or the protection and control relay itself," said Vinayagam. "Time-based monitoring also does not allow for real-time data collection, which can help operators to make asset decisions proactively."

To help compensate for the drawbacks of time-based monitoring, refiners integrate devices called protection and control (P&C) relays into their facility electrical systems to prevent unplanned outages.

"A P&C relay monitors a specific asset – or assets – in the electrical system and can be programmed to control the action(s) that will be taken in the event of an anomaly in the system or with the asset itself," Vinayagam noted. "P&C relays are an integral part of an oil refinery's electrical system because the system relies on numerous assets – motors, feeders, etc. – which handle critical loads in the system and keep the refinery's system operating."

GE Digital Energy recently introduced a next-generation P&C relay technology – marketed under the brand name Multilin 8 Series – that integrates condition-based monitoring, which is meant to place less emphasis on time-based monitoring.

"Condition-based monitoring means that the relay collects data on the health of the asset(s) it is protecting and controlling," said Vinayagam, adding that the technology also tracks the health of the relay itself.

It "allows operators to get a real-time view of the assets on the system and a better understanding of what assets require maintenance or, in some cases, replacement," Vinayagam noted.

"Condition-based monitoring delivers both asset and device protection," he said. "In layman's terms, the 8 Series takes the heartbeat of the asset it's protecting, as well as its own, and feeds that data back to the system operator who can then take action to prevent unplanned outages."

According to GE, the new P&C relay platform is built to withstand harsh conditions such as high levels of vibration and high humidity that can accelerate corrosion. The device's printed circuit boards feature a standard harsh conformal coating to enhance protection against the elements, added the company.

"We understand that our customers' electrical infrastructures are mission critical to their operations," concluded Juan Macias, general manager, grid automation for GE's Digital Energy business. "This new platform takes advantage of advances in technology and design approach to maximize reliability and product life."