Panamanian Utility Improves Transmission System Stability With Wide-Area Protection Scheme

Challenge

In 2017 and 2018, Panama suffered major blackouts that also caused undesirable effects in the other countries that are part of the Central American regional power system.

Demand and generation in Panama have grown quickly, and the development of additional transmission capacity has been delayed. In addition, unique geographical constraints make system operation challenging.

Panama’s 230 kV transmission backbone is 400 km (248.55 mi) long. The biggest load centers are in the east, but major generation sources and interconnections to the Central American regional power system are in the west. The load center operates very close to the power voltage curve limit; various contingencies have led to instantaneous voltage collapse, fault-induced delayed voltage recovery, and uncontrolled load shedding.

Solution

Remedial action schemes (RASs) provide integrated wide-area protection and control that improves transmission system reliability and stability. The RAS developed by SEL is a high-speed, contingency-based adaptive load-shedding system that uses SEL logic processors, open-line detection algorithms, and wide-area, high-speed communications to ensure system stability.

Engineers at Empresa de Transmisión Eléctrica, S.A. (ETESA), Panama’s transmission system operator, collaborated with SEL to model the power system, define and develop the RAS implementation, and commission the system. 

SEL built and tested the panels in its own advanced facilities, running extensive simulations of Panama’s power system with control hardware in the loop. These tests validated the response of the controllers and the rest of the RAS system in many different scenarios—and made it possible to find and correct for conditions that weren’t considered in the initial design, thus reducing commissioning time onsite.

Results

The SEL powerMAX RAS system was commissioned in 2021. It has worked as designed, maintaining electrical power system stability in Panama, taking care of the link with the rest of Central America, and reducing the possibility of blackouts, voltage collapse, overload of lines, and slow voltage recovery. Incorporating SCADA information from distribution companies in real time helps optimize load-shedding decision making. 

And because the new system has also increased the transmission system power transfer limit, the national utility is now able to reduce operating costs and carbon emissions by using more hydropower and optimizing the operation of its wind and solar resources.