Applicability of Synchrophasor Based Frequency Data for Protection and Control Applications Nuwan Perera, Rene Midence ERLPhase Power Technologies Ltd. Winnipeg, MB, Canada nperera@erlphase.com Nandaka Jayasekara Manitoba Hydro Winnipeg, MB, Canada Abstract—Synchrophasor based wide area monitoring, protection, and control applications are widely used all over the world. The latest IEEE synchro-phasor standard C37.118.1a- 2014 provides necessary steady-state and dynamic performance requirements for two different application categories namely the “Protection (P) Class” and the “Metering (M) Class” [1-2]. Satisfactions of these application classes require inclusion of digital filters into the standard phasor calculations. Although the IEEE standard provides benchmark test cases for dynamic and steady state frequency measurements, from application point of view, it is essential to understand their applicability for various protection and control applications specified by authorities and standards such as NERC, BAL-0003-1. The information discussed in this paper is useful for users to understand the impact of the performance filters introduced in the latest synchro-phasor standard applicable for frequency related power system applications. Keywords— synchrophasor, PMU, proteciton, control, frequency I. INTRODUCTION This section provides a brief introduction to frequency calculation methods, performance filters and their intended applications. A. Power Frequency Calculations Power frequency calculations can be performed in many different ways. Out of these methods, the zero crossing method is considered as the most established method. However, most of the digital fault recorders application uses the rate of change of phase angle calculation method for frequency estimations. The IEEE synchro-phasor standard C37.118.1a-2014 also recommends the same method assuming that the calculations are performed in relation to the nominal sampling rates, i.e. non frequency tracking calculations. This method calculates frequency deviations with respect to the nominal frequency and use to derive the actual frequency and the rate of change of frequency calculations. B. Performance Classes The IEEE synchro-phasor standard provides two filter classes P class and M class. The P class has been proposed for applications requiring fast response and mandates no explicit filtering. The M class has been proposed for applications that could be adversely effected by aliased signals and do not require the fastest reporting speed. C. Impact of Performance Class Filters and Suitability for Different Applications Filtering methods applied for above two classes are different and output response depends on the nature of the filter. Thus, the standard recommends careful consideration and analysis of application requirements before selecting a suitable filter class. In addition, accuracy requirements are different for two filter classes. All these factors make the filter selections complicated for the end user. II. SIMULATION BASED INVESTIGATION This section of the paper provides the steps involved with simulation based investigations carried out to evaluate the performance of different class of filters [4], beyond the standard frequency requirements. The results from the standard test cases are discussed to highlight the application challenges. A. Hardware Test Setup Fig.1 shows the test setup used to test and evaluate the performance of the PMU. Fig. 1: PMU Test Setup Using a Real Time Digital Simulator B. PMU Setting A setting example for PMU filter class selection including other details is shown in Fig .2.