Measurement Errors and Delays on Wide-Area Control Based on IEEE Std C37.118.1-2011: Impact and Compensation

Abstract

Wide Area Control (WAC) of power systems is highly depended on synchronized measurements provided by the Phasor Measurement Units (PMUs). However, the contemporary measurement chain and the communication network are far from ideal. Therefore, it is essential to identify the impact of the availability and quality of the synchronized measurements, on the wide area controller's performance. This paper examines the effect of measurement errors and delays/dropouts on the damping capability of the wide area controller. The measurement errors considered in this work are according to the dynamic compliance requirements of the PMU during disturbances as it is imposed in the IEEE Synchrophasor Standard C37.118.1-2011. The delays are separated into measurement and feedback delays. The results indicate that delays along with dropouts deteriorate significantly the WAC performance, while the consideration of only the measurement errors (steady-state and dynamic) in the simulation environment has a minor effect on its operation. For this reason, a linear predictor is proposed to compensate effectively and timely all the system's delays. The case studies are conducted on the IEEE 39-bus system and evaluated through the Prony analysis tool.

Wide Area Control of Governors and Power System Stabilizers With an Adaptive Tuning of Coordination Signals

“…In [15] the rotor angle is assumed to be available as well, but in reality, the majority of the commercial PMUs cannot provide it. For this reason, the rotor angle is calculated using synchronized voltage and current measurements, according to [19]. Therefore, by expressing all the generator vectors into the d-q frame and by considering only the d-axis, the rotor angle (relative to the terminal voltage of the generator) can be calculated as follows:…”

“…T CHkṖCHk = P GVk − P CHk (18) T RHkṖRHk = P CHk − P RHk (19) where P CH and P RH represent the steam pressure and the reheated steam pressure in per unit, respectively. The derived equations describing the governor operation are:…”

“…Therefore, in order to consider realistic conditions into the real-time simulation, the proposed scheme is tested under the presence of realistic measurement errors. To achieve this, the procedure presented in [19] is adopted here. More specifically, in [19] the authors have applied realistic measurement errors to identify the impact of measurement quality and accuracy on the ConvWAC performance.…”

“…Furthermore, the coherency concept is required in this work in order to reduce the number of PMUs needed by the proposed scheme. Finally, both measurement errors and data delays/dropouts, as described in [19], have been considered for the testing of the proposed scheme. As indicated in [19], the data delays (which impact more the WAC performance) can be overcome successfully through the use of a linear predictor.…”

“…Finally, both measurement errors and data delays/dropouts, as described in [19], have been considered for the testing of the proposed scheme. As indicated in [19], the data delays (which impact more the WAC performance) can be overcome successfully through the use of a linear predictor. In this sense, data delays are out of the scope of this paper.…”