To expand bulk electric system visibility and enable PJM to better detect High Impact Low Frequency dynamic events and perform its reliability obligations, PJM stakeholders endorsed an initiative to expand the installation of synchrophasor technology across the grid.
Going forward, the installation of synchrophasor measurement devices will be required for new planning projects (meeting voltage level and other substation criteria) submitted to the Regional Transmission Expansion Plan (RTEP) after June 1, 2021.
“Having synchrophasors installed across the system allows operators to view it as if it were a 4K HD video. That allows us to see things we have never measured before,” said PJM Senior Business Solution Engineer Shaun Murphy. “PJM uses this high speed, real time data to closely monitor system conditions.”
PJM has also just released a new video through its Learning Center, called “Understanding Synchrophasors,” that helps explain synchrophasor technology and its important role for more precise and responsive grid operations and planning.
Faster Monitoring, Better Detail, Precision Planning
Synchrophasors, also known as Phasor Measurement Units (PMUs), record data at a rate of 30 times per second. Each measurement is a snapshot of voltage, frequency and current. Time-stamped and precision-aligned with GPS satellite signals, this data is collected, synchronized and combined to produce comprehensive, high resolution views of the transmission system.
Synchrophasors allow grid operators to pinpoint the location and exact time of a frequency disturbance on the system, and perform other valuable applications like Linear State Estimation. Synchrophasors can also detect high-speed disturbances like power system oscillations and electrical islands that traditional SCADA measurements simply cannot capture, Murphy said.
PJM also analyzes synchrophasor data to improve the dynamic models of generators, which are critical to bulk electric system planning and operations. For continual improvement, simulations are performed and adjusted against the real-world synchrophasor data recorded during a power system disturbance.
Meeting the Challenges of Our Evolving Grid
PMUs are not new. PJM’s Applied Innovation Department has been collaborating with stakeholders and industry experts to study and implement practical and efficient applications of PMU technology for nearly a decade. Member Transmission Owners, for example, already stream synchrophasor data from more than 125 substations in 10 states to PJM. The new requirements recently approved by stakeholders broaden this longstanding practice in the field.
Read more about synchrophasors and other electricity industry topics on the PJM Learning Center.