Recent Development of Frequency Estimation Methods for Future Smart Grid

Abstract

The frequency estimated by the Phasor Measurement Unit (PMU) is a critical index of power system status and supports many smart grid applications. The future smart grid features high penetration of renewables and more fast-moving power electronics inverters but raises challenges to the reliable frequency estimation. This paper presents three methods to address these challenges. First, an enhanced zero-crossing algorithm was developed to track the fast-changing frequency in system dynamics. Second, we propose a technology that can tolerate the system transient and suppress the outliers. Third, an algorithm was developed to export high time-resolution frequency estimations with minimum computational effort. All of the proposed methods are realized in hardware and compared with classical frequency estimation methods. The testing results indicate that the proposed methods have excellent performance. They can be used in future PMUs and provide reliable and high time resolution data for smart grid applications.

Power Distribution System Synchrophasor Measurements With Non-Gaussian Noises: Real-World Data Testing and Analysis

“…For example, Wang et al analyze real PMU measurements and reveal that the PMU measurement errors do not follow a Gaussian distribution [9]; and Mili et al assess the sensitivity of different state estimators to Gaussian/non-Gaussian noises and develop a robust state estimator to cope with non-Gaussian measurement errors [10]. Now synchrophasor systems are being extensively deployed in distribution systems, such as the micro-PMU (µPMU) network [11], [12] and the frequency disturbance recorder (FDR)-based FNET/GridEye [13], [14] as shown in Fig 1.…”

IEC 61850-9-2 based module for state estimation in co-simulated power grids

“…This is a great opportunity to improve the development of measurement equipment, the connectivity, and data management of multiple PMUs prototypes with better hardware and software design. However, certain challenges are focused on the application to improve monitoring, control, dynamic state estimation, protective schemes, cybersecurity and complex solutions for our modern power systems [3]. It has been also proposed the integration of these devices not only at the transmission level for example for voltage stability with online PMU measurements [6], [7] but also distribution systems [8], [9] and microgrids [10].…”

“…This paper presents a scalable simulation platform to assess state estimation solutions with real-time testing, hardware in the loop integration of measurement equipment (OpenPMU), and the use of virtual PMUs with IEC61850-9-2. There are some research tools available such as GridTeractions, a laboratory that allows testing smart and advanced algorithms for modern power grids [3] where many applications are synchronized with an emulated communication network through transmission control protocol/internet protocol (TCP/IP) communication.…”

Three‐phase algorithm for independent single‐phase grid frequency estimation under grid disturbances

“…IET Generation, Transmission & Distribution published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology. [7]. For this purpose, various research works have been published in the technical literature.…”

“…A digital signal processing (DSP) method should generate quick and precise frequency estimation under grid disturbances [7]. For this purpose, various research works have been published in the technical literature.…”