Your browser does not support JavaScript!

access icon free Electronic transformer performance evaluation and its impact on PMU

The electronic transformer of smart substations, which transfers primary signals, is important for measurements and controls. In this study, the transformation characteristics of a Rogowski electronic current transformer (ECT) are analysed theoretically. Then, experimental platforms are established to verify the analysis and study the impact of the transformation characteristics of the ECT and an electronic voltage transformer (EVT) on a phasor measurement unit (PMU) using standard test signals. The analysis and the testing results show that this ECT can transfer the phasor well under both steady and dynamic conditions. However, the harmonics introduced by the ECT may lead to the measurement errors of frequency and the rate of the change of the frequency (ROCOF) from the PMU. Therefore, a phasor algorithm with powerful DC offset and harmonics immunity is suggested for PMUs connected to the output of this type of ECT. For the EVT, the ROCOF measurements are easily affected as well. The EVT was also shown to be more sensitive to temperature than the potential transformer (PT).


    1. 1)
      • 16. Wu, W., Xu, Y., Xiao, X., et al: ‘Research on proximity effect in measuring error of active electronic voltage transformers’, IEEE Trans. Instrum. Meas., 2016, 65, (1), pp. 7887.
    2. 2)
      • 22. IEEE Standard for Synchrophasor Measurements for Power Systems, IEEE Standard C37.118.1-2011, December 2011.
    3. 3)
      • 6. Cai, D., Regulski, P., Osborne, M., et al: ‘Wide area inter-area oscillation monitoring using fast nonlinear estimation algorithm’, IEEE Trans. Smart Grid, 2013, 4, (3), pp. 17211731.
    4. 4)
      • 11. Liu, H., Bi, T., Yang, Q.X.: ‘The evaluation of phasor measurement units and their dynamic behavior analysis’, IEEE Trans. Instrum. Meas., 2013, 62, (6), pp. 14791485.
    5. 5)
      • 1. Liu, H., Bi, T., Li, J., et al: ‘An inter-harmonics monitoring method based on PMUs’, IET Gener. Transm. Distrib., 2017, 11, (18), pp. 44144421.
    6. 6)
      • 17. Wang, D., Mao, C., Lu, J.: ‘Modelling of electronic power transformer and its application to power system’, IET Renew. Power Gener., 2007, 1, (6), pp. 887895.
    7. 7)
      • 4. Flack, G., Kolevar, K.: ‘Final report on the implementation of the task force recommendations’, Natural Resources Canada, Ontario and U.S. Department of Energy, Washington DC, USA, September 2006.
    8. 8)
      • 10. Bi, T., Liu, H., Feng, Q., et al: ‘Dynamic phasor model-based synchrophasor estimation algorithm for M-class PMU’, IEEE Trans. Power Deliv., 2015, 3, (3), pp. 11621171.
    9. 9)
      • 5. Zhang, X., Belmans, P., Kirschen, D.: ‘Guest editorial introduction to the special section on planning and operation of transmission grid with applications to smart grid—from concept to implementation’, IEEE Trans. Smart Grid, 2013, 4, (3), pp. 16191620.
    10. 10)
      • 14. Pasini, G., Peretto, L., Roccato, P., et al: ‘Traceability of low-power voltage transformer for medium voltage application’, IEEE Trans. Instrum. Meas., 2014, 63, (12), pp. 14791485.
    11. 11)
      • 8. Liu, H., Li, J., Li, J., et al: ‘Synchronised measurement devices for power systems with high penetration of inverter-based renewable power generations’, IET Renew. Power Gener., 2019, 13, (1), pp. 4048.
    12. 12)
      • 18. Bi, T., Liu, H., Zhou, X., et al: ‘Impact of transient response of instrument transformers on phasor measurements’. Proc. IEEE Power Engineering Society General Meeting, Minneapolis, MN, 2010, pp. 16.
    13. 13)
      • 21. Technology Specification of Power System Real Time Dynamic Monitoring System, Q/GDW 1131-2014, 2015.
    14. 14)
      • 15. Skubis, T., Piaskowy, A.: ‘Calibration and leakage impedance measurements of a standard 1:2 ratio autotransformer inductive voltage divider’, IEEE Trans. Instrum. Meas., 2015, 64, (2), pp. 494501.
    15. 15)
      • 20. Stenbakken, G.N.: ‘Calculating combined amplitude and phase modulated power signal parameters’. Proc. IEEE Power Engineering Society General Meeting, Detroit, MI, 2011, pp. 17.
    16. 16)
      • 2. Usman, M., Faruque, M.O.: ‘Validation of a PMU-based fault location identification method for smart distribution network with photovoltaics using real-time data’, IET Renew. Power Gener., 2018, 12, (21), pp. 58245833.
    17. 17)
      • 12. Tang, Y., Stenbakken, G.N., Goldstein, A.: ‘Calibration of phasor measurement unit at NIST’, IEEE Trans. Instrum. Meas., 2013, 62, (6), pp. 14171422.
    18. 18)
      • 9. Persson, M., Chen, P.: ‘Frequency evaluation of the Nordic power system using PMU measurements’, IET Renew. Power Gener., 2017, 11, (11), pp. 28792887.
    19. 19)
      • 3. Zhang, C., Jia, Y., Xu, Z., et al: ‘Optimal PMU placement considering state estimation uncertainty and voltage controllability’, IET Renew. Power Gener., 2017, 11, (18), pp. 44654475.
    20. 20)
      • 7. Phadke, A.G.: ‘Synchronized phasor measurements in power systems’, IEEE Comput. Appl. Power, 1993, 2, (2), pp. 1015.
    21. 21)
      • 23. The Test Specification for Automation Equipment in Smart Substation Part6: Phasor Measurement Unit, Q/GDW 11202.6-2014, 2015.
    22. 22)
      • 13. Frigo, G., Colangelo, D., Derviškadić, A., et al: ‘Definition of accurate reference synchrophasors for static and dynamic characterization of PMUs’, IEEE Trans. Instrum. Meas., 2017, 66, (9), pp. 22332244.
    23. 23)
      • 19. Bi, T., Sun, F., Liu, H.: ‘Rogowski electronic transformer performance evaluation and its impact on PMUs’. IFAC Workshop on Control of Transmission and Distribution Smart Grids CTDSG 2016, Prague, Czech Republic, 2016, pp. 17.

Related content

This is a required field
Please enter a valid email address