Real-Time Area Angle Monitoring Using Synchrophasors: A Practical Framework and Utility Deployment

Abstract

This paper develops a practical framework of Area Angle Monitoring (AAM) to monitor in real time the stress of bulk power transfer across an area of a power transmission system. Area angle is calculated from synchrophasor measurements in real time to provide alert to system operators if the area angle exceeds pre-defined thresholds. This paper proposes a general method to identify the warning threshold of area angle and a simplified method to quickly update area angle thresholds under significant topology change. A mitigation strategy to relieve the area stress is also proposed. In order to handle the limited coverage of synchrophasor measurements, this paper proposes a method to estimate phase angles for boundary buses without synchrophasor measurements, which extends the application scenario of AAM. AAM is verified for a power transmission area in the Western Electricity Coordinating Council system with both simulated data and synchrophasor measurements recorded from real events. A utility deployment for real-time application of AAM with livestream and recorded synchrophasor data is described.

The Circular Variance as a Visual Summary of Synchronized Voltage Angle Measurements

“…For corridors containing multiple transmission lines, the phase angle difference across the corridor can provide useful information about stress that may not be apparent in power flows [6]. This concept can be extended to evaluate the stress of an area with boundaries monitored by PMUs [7,8,9]. Voltage angle pairs can also serve as a stress indicator at the interconnection-scale [10].…”

Data analytics for real-time event identification using real phasor measurement unit data

“…Also, the robustness of the model should be considered because data quality problems are common in current PMUs. Several previous works have mentioned the impact of data quality problems in data-driven event identification tasks Ju et al (2020); Ju et al (2021). Here, we also provide a basic statistical analysis, survival function, on our 20TB PMU dataset to show the probability of occurrence of data quality problems.…”

“…When the 2-second event dataset is obtained, PMU status flags information is utilized to perform data quality assessment Ju et al (2021). The status flags are in binary form and all information is aligned as 16-bit long.…”

“…Recent years have seen rapid growth in the deployment of phasor measurement units (PMUs), providing a unique opportunity for preventing cascading failures and blackouts Ju et al (2021).…”