Harsh Vardhan harsh.vardhan@alstom.com Performance evaluation of Phasor Measurement Units for digital substations (PMU with IEC 61850 sampled values) Harsh Vardhan harsh.vardhan@alstom.com
Objectives Application of IEC 61850 Process Bus in Synchronized Phasor Measurements Systems Assembly and testing of a PMU using Sampled Values (SV) for acquiring data Presentation and discussion of test results for "PMU with SV“ under different scenarios Real electrical system measurements at low voltage (MedFasee Project) under Normal system operation under disturbance Laboratory tests
The Digital Substation PMU with SV
The Merging Unit IEC 61850-9-2LE sampled values (SV) and IEC 61850-8-1 GOOSE interface Operates with protection profiles (80 samples/cycle) and measuring (256 samples/cycle) Sampling stability guaranteed by hardware Synchronization via Ethernet PTPv2 or via IRIG-B Use of VLANs and priority tags (802.1Q)
IEEE C37.118.1-2011 definitions TVE (Total Vector Error): FE (Frequency Error): RFE (Rate of Change of Frequency Error):
Assessment Standards - Dynamic Testing Delay time: Transition delay of the measured variables Response time: Errors stabilization time Source: IEEE C37.118.1-2011
Test System Architecture: Comparison of Synchrophasors measured by the "PMU with SV" and the “conventional PMU” System under normal operation conditions System under disturbance
Measurements - Normal System Operation 0.01% 0.31 deg
Measurements - Normal System Operation 1.7mHz
Measurements - Under Disturbance
Measurements - Under Disturbance
Measurements - Under Disturbance
Laboratory Tests Rates: 20 FPS 60 FPS Class M limits: Architecture IEEE C37.118.1-2011 C37.118.1a IEEE-2014 Steady state test: Change Frequency, and Angle Module Dynamic test: Step magnitude and Angle MU SV profiles: Protection Profile (PP) – 80 samples/cycle Measuring profile (PM) - 256 samples/cycle Architecture
Laboratory Tests Frequency range: 55 Hz to 65 Hz (1 Hz steps) 20 FPS 20 FPS 60 FPS TVE (%) FE (mHz) RFE (mHz/s) Maximum Limits 1,00 5,00 100,0 PMU SV (PP) 0,26 0,57 14,65 0,20 1,29 108,5 PMU SV (MP) 0,35 0,71 16,57 0,28 0,84 60,20 PMU conventional 0,48 14,88 0,21 0,89 56,99
Laboratory Tests Magnitude and angle Variations: 10% to 120% Vn 10% 200% In Limits TVEmáx = 1,00% Magnitude Variation Angle Variation 20 FPS 60 FPS PMU SV (PP) 0,35 0,90 0,08 0,09 PMU SV (MP) 0,39 0,36 0,13 0,06 PMU conventional 0,47 0,46 0,10 0,07 Observation: Larger TVEs found at lower current levels (10% In).
Laboratory Tests PMU SV (PP) PMU SV (PP) Magnitude and angle Variations - 20 FPS: Delay time Equipment Magnitude Angle Limits 12,5ms PMU SV (PP) 5,0ms PMU SV (MP) PMU conventional Overshoot Equipment Magnitude Angle Limits 10% PMU SV (PP) 0,20% 0,60% PMU SV (MP) 0,36% PMU conventional 0,17% 0,72% Response time Equipment Magnitude Step Angle Step TVE (1%) FE (5mHz) RFE (100mHz/s) Limits 0,35s 0,70s PMU SV (PP) 0,10s 0s 0,12s 0,21s 0,25s PMU SV (MP) 0,26s PMU conventional 0,08s 0,38s
Laboratory Tests PMU SV (PP) PMU SV (PP) Magnitude and angle Variations - 60 FPS: Delay time Equipment Magnitude Angle Limits 4,17ms PMU SV (PP) 1,67ms PMU SV (MP) PMU conventional Overshoot Equipment Magnitude Angle Limits 10% PMU SV (PP) 0,56% 0,37% PMU SV (MP) 0,35% 0,41% PMU conventional 0,52% 0,34% Response time Equipment Magnitude Step Angle Step TVE (1%) FE (5mHz) RFE (100mHz/s) Limits 0,117s 0,2330s 0,233s PMU SV (PP) 0,032s 0s 0,038s 0,085s 0,115s PMU SV (MP) 0,082s PMU conventional 0,002s 0,035s 0,112s 0,128s
Key Findings Feasibility of using MU in SMSF The "PMU with SV" reproduced faithfully the Synchrophasors measured by “conventional PMU” in various power system operating conditions and in laboratory tests. The measurement profile (PPC 256) proved the most suitable for use with PMUs Larger TVEs found at lower current levels (10% In). PMUs using SV (IEC 61850-9-2LE) allows the calculation of Synchrophasors from optical Instrument Transformers Since 02/2014 the Synchrophasors at the "UFSC" point in the SMSF BT MedFasee project are measured by a "PMU with MU"
Thank You! Questions?