A Method for the Measurement of Digitizers’ Absolute Phase Error

A lot of engineering applications, from telecommunications to power systems, require accurate measurement of phase angles. Some of them, like synchrophasor measurement and calibration of instrument transformers with digital output, in order to reach high phase measurement accuracy, require the knowledge of phase error of digitizers. Therefore, in this paper a method for the measurement of digitizers’ absolute phase errors is proposed. It adopts a sinewave and two square waves, that are the digitizer sample clock and a phase reference signal. Combining the measurements of the relative phase differences between the adopted signals it is possible to accurately evaluate the absolute phase error of a digitize

A Software-based Low-Jitter Servo Clock for Inexpensive Phasor Measurement Units

This paper presents the design and the implementation of a servo-clock (SC) for low-cost Phasor Measurement Units (PMUs). The SC relies on a classic Proportional Integral (PI) controller, which has been properly tuned to minimize the synchronization error due to the local oscillator triggering the on-board timer. The SC has been implemented into a PMU prototype developed within the OpenPMU project using a BeagleBone Black (BBB) board. The distinctive feature of the proposed solution is its ability to track an input Pulse-Per-Second (PPS) reference with good long-term stability and with no need for specific on-board synchronization circuitry. Indeed, the SC implementation relies only on one co-processor for real-time application and requires just an input PPS signal that could be distributed from a single substation clock

New Efficiency Monitoring and Control Technology Using Synchrophasors

In this paper we describe the synchrophasorbasedWAM technology particularly with regard to usage indistribution networks. The information contained herecomes out from experience with deployment and operationof the WAM system in distribution companies in the CzechRepublic

An extended Kalman filter approach for accurate instantaneous dynamic phasor estimation

This paper proposes the application of a non-linear Extended Kalman Filter (EKF) for accurate instantaneous dynamic phasor estimation. An EKF-based algorithm is proposed to better adapt to the dynamic measurement requirements and to provide real-time tracking of the fundamental harmonic components and power system frequencies. This method is evaluated using dynamic compliance tests defined in the IEEE C37.118.1-2011 synchrophasor measurement standard, providing promising results in phasor and frequency estimation, compliant with the accuracy required in the case of off-nominal frequency, amplitude and phase angle modulations, frequency ramps, and step changes in magnitude and phase angle. An important additional feature of the method is its capability for real-time detection of transient disturbances in voltage or current waveforms using the residual of the filter, which enables flagging of the estimation for suitable processing

Synchrophasor Technology And Applications: Benefits Over Conventional Measurements

The purpose of this thesis is to investigate the benefits of synchrophasor technology in bulk power system measurements. To accomplish this task, multiple methods of investigation and analysis have been conducted. First, a better understanding of the synchrophasor power measurement systems was achieved through a literature review. The review provided some perspective on the differences between these systems and the conventional systems of power measurements. Then, some utility grade data was acquired and analyzed. In this process, there were some aspects of confidentiality, and that required an added layer of discretion. However, the process made it possible to analyze a variety of authentic measurements from the power system. This analysis provides novelty to the utility industry, but the experience of physical implementation wasn’t available through this process. Finally, efforts were directed toward a physical demonstration of a synchrophasor measurement system. A test bed system was configured, and measurements were obtained from the system through phasor measurement units (PMUs). In an attempt to extent this demonstration effort, simulation options were investigated as well. Unfortunately, there are some limitations with the available equipment. Overall, this provided novelty to academia through a physical implementation of this technology. With changing demand, transmission, desires for efficiency, and an evolving generation fleet, extensive grid knowledge is important for maintaining a reliable power system