Harmonic PMU Algorithm Based on Complex Filters and Instantaneous Single-Sideband Modulation

Abstract

Phasor measurement units (PMUs) have become powerful monitoring tools for many applications in smart grids. In order to address the different issues related to harmonics in power systems, the fundamental phasor estimator in a PMU has been extended to the harmonic phasor estimator by several researchers around the world. Yet, the development of harmonic phasor estimators is a challenge because they have to consider time-varying frequencies since the frequency deviation in the harmonic components is proportional to the harmonic order in a dynamic way. In this work, a new algorithm for harmonic phasor estimation using an instantaneous single-sideband (SSB) modulation is presented. Unlike other SSB-based approaches, its implementation in this work is based on concepts of instantaneous phase and instantaneous frequency. In general, the proposed algorithm is divided into two stages. Firstly, the estimation of the fundamental phasor is carried out by means of a complex finite impulse response (FIR) filter which provides the analytic signal used to compute the instantaneous magnitude, phase, and frequency. Secondly, a complex FIR filter bank is proposed for the estimation of the harmonic components, where the instantaneous SSB modulation technique is applied in order to center the harmonic components into specific narrow bands for each complex filter when an off-nominal frequency occurs. The validation of the proposed algorithm is carried out by means of the current standards of phasor measurement units, i.e., Std. C37.118.1-2011 and C37.118.1a-2014, which involve steady-state, dynamic, and time performance tests.

A New Phasor Estimator for PMU Applications: P Class and M Class

“…Linear phase FIR filters are commonly used due to their stability and immunity to the phase distortion [21]. In this sense, a brick-wall filter is considered as an idealized filter with a rectangular frequency response and an abrupt transition between the passband and the stopband [22]. The impulse response for a low-pass filter h LP is given by a sinc function as follows:…”

A Low-Cost Test Platform for Performance Analysis of Phasor Measurement Units

“…It should be pointed out that in [3,17,40], authors use an emulated GPS signal for low-cost PMU testing purposes. However, more realistic test platforms are necessary for research and validation of new algorithms as well as for comparison of various algorithms used to determine syncrophasors [24,25,[41][42][43][44][45]. Moreover, a custom-made test platform should have the possibility of performing additional test case studies for the purpose of academic research, which usually goes beyond what is possible with commercially available PMU calibrators.…”

Estimação Robusta De Estados Harmônicos Considerando Supressão De Erros Grosseiros: Uma Abordagem Usando Um Modelo De Otimização / a Robust Harmonic State Estimation Considering Bad Data Suppression: An Approach Using an Optimization Model

“…Para isso, um supercalibrador foi desenvolvido em [8] para extirpar erros grosseiros e sistemáticos garantindo a aplicação viável de PMUs e estimação de estados harmônicos. Desde este projeto, outros sistemas de monitoramento foram concebidos e até mesmo outros modelos de PMUs foram propostos para contemplar análise harmônica como em [10] e [11].…”