In this paper it is shown that M class PMU (Phasor Measurement Unit) reference model for phasor estimation recommended by the IEEE Standard C37.118.1 with the Amendment 1 is not compliant with the Standard. The reference filter preserves only the limits for TVE (total vector error), and exceeds FE (frequency error) and RFE (rate of frequency error) limits. As a remedy we propose new filters for phasor estimation for M class PMU that are fully compliant with the Standard requirements. The proposed filters are designed: 1) by the window method; 2) as flat-top windows; or as 3) optimal min-max filters. The results for all Standard compliance tests are presented, confirming good performance of the proposed filters. The proposed filters are fixed at the nominal frequency, i.e. frequency tracking and adaptive filter tuning are not required, therefore they are well suited for application in lowcost popular PMUs.
 Synchrophasor Measurements for Power Systems, IEEE Standard C37.118.1, Dec. 2011.
 Synchrophasor Measurements for Power Systems − Amendment 1: Modification of Selected Performance Requirements, IEEE Standard C37.118.1a, Apr. 2014.
 Phadke, A.G., Thorp J.S. (2008). Synchronized Phasor Measurements and Their Applications. Springer.
 Phadke, A.G., Thorp J.S. (2009). Computer Relaying For Power Systems. John Wiley and Sons.
 Premerlani, W., Kasztenny, B., Adamiak, M. (2008). Development and implementation of a synchrophasor estimator capable of measurements under dynamic conditions. IEEE Trans. Power Del., 23(1), 109-123.
 Phadke, A., Kasztenny, B. (2009). Synchronized phasor and frequency measurement under transient conditions. IEEE Trans. Power Del., 24(1), 89-95.
 Macii, D., Petri, D., Zorat, A. (2012). Accuracy analysis and enhancement of DFT-based synchrophasor estimators in off-nominal conditions. IEEE Trans. Instrum. Meas., 61(10), 2653-2664.
 Belega, D., Petri, D. (2013). Accuracy analysis of the multicycle synchrophasor estimator provided by the interpolated DFT algorithm. IEEE Trans. Instrum. Meas., 62(5), 942-953.
 Petri, D., Fontanelli, D., Macii, D. (2014). A frequency-domain algorithm for dynamic synchrophasor and frequency estimation. IEEE Trans. Instrum. Meas., 63(10), 2330-2340.
 Barchi, G., Fontanelli, D., Macii, D., Petri, D. (2015). On the Accuracy of Phasor Angle Measurements in Power Networks. IEEE Trans. Instrum. Meas., 64(5), 1129-1139.
 Barchi, G., Macii, D., Petri, D. (2013). Synchrophasor estimators accuracy: A comparative analysis. IEEE Trans. Instrum. Meas., 62(5), 963-973.
 Barchi, G., Macii, D., Belega, D., Petri, D. (2013). Performance of synchrophasor estimators in transient conditions: A comparative analysis. IEEE Trans. Instrum. Meas., 62(9), 2410-2418.
 de la O Serna, J.A. (2007). Dynamic Phasor Estimates for Power System Oscillation. IEEE Trans. on Instrum. Meas., 56(5), 1648−1657.
 Platas-Garza, M. A., de la O Serna, J. A. (2010). Dynamic phasor and frequency estimates through maximally flat differentiators. IEEE Trans. Instrum. Meas., 59(7), 1803-1811.
 de la O Serna, J. A. (2015). Synchrophasor Measurement With Polynomial Phase-Locked-Loop Taylor- Fourier Filters. IEEE Trans. on Instrum. Meas., 64(2), 328−337.
 Belega, D., Fontanelli, D., Petri, D. (2015). Dynamic Phasor and Frequency Measurements by an Improved Taylor Weighted Least Squares Algorithm. IEEE Trans. Instrum. Meas., 64(8), 2165-2178.
 Belega, D., Macii, D., Petri, D. (2014). Fast synchrophasor estimation by means of frequency-domain and time-domain algorithms. IEEE Trans. Instrum. Meas., 63(2), 388-401.
 Roscoe, A.J., Dickerson, B., Martin, K.E. (2015). Filter Design Masks for C37.118.1a-Compliant Frequency- Tracking and Fixed-Filter M-Class Phasor Measurement Units. IEEE Trans. on Instrum. Meas., 64(8), 2096−2107.
 Roscoe, A.J., Abdulhadi, I.F., Burt, G.M. (2013). P and M class phasor measurement unit algorithms using adaptive cascaded filters. IEEE Trans. Power Del., 28(3), 1447-1459.
 Roscoe, A.J. (2013). Exploring the relative performance of frequency-tracking and fixed-filter phasor measurement unit algorithms under C37.118 test procedures, the effects of interharmonics, and initial attempts at Mering P-class response with M-class filtering. IEEE Trans. Instrum. Meas., 62(8), 2140-2153.
 Kamwa, I., Samantaray, S.R., Joos, G. (2014). Wide Frequency Range Adaptive Phasor and Frequency PMU Algorithms. IEEE Trans. Smart Grid., 5(2), 569-579.
 Kamwa, I., Samantaray, S., Joos, G. (2013). Compliance analysis of PMU algorithms and devices for widearea stabilizing control of large power systems. IEEE Trans. Power Syst., 28(2), 1766-1778.
 Castello, P., Liu, J., Muscas, C., Pegoraro, P.A., Ponci, F., Monti, A. (2014). A fast and accurate PMU algorithm for P+M class measurement of synchrophasor and frequency. IEEE Trans. Instrum. Meas., 63(12), 2837-2845.
 Martin, K.E. (2015). Synchrophasor measurements under the IEEE standard C37.118.1-2011 with amendment C37.118.1a. IEEE Trans. Power Del., 30(3), 1514-1522.