CCET Discovery Across Texas Data Quality Plan - Overview November 15, 2012 John Ballance – EPG

Data Quality Plan In order for ERCOT to achieve a production quality phasor monitoring that can be relied upon in real-time operations, three conditions must be met: The data must be flowing reliably from the PMU to the operator’s console, The data must be valid, and The data must be monitoring the critical locations (right places). The Data Quality Plan will address the first condition 10.11.12

Dropout is Observable RTDMS Reports show significant dropout data on some signals (60-99%) Observation of ePDC Management Tool shows major dropouts (60-99%) in real-time data streams Data availability testing performed on the RTDMS DB confirms the presence of data dropouts Examination of one-second and one-minute tables in RTDMS database confirms down sampled data is missing on signals as well 10.11.12

Goals Identify nodes in phasor network affecting data availability (i.e., data dropouts) Classify identified dropout issues by severity and frequency Determine likely causes of data dropouts at identified locations Propose solutions to help eliminate identified data availability problems 10.11.12

Phasor Data Network AEP ePDC Oncor PDC Phasor Archiver Phasor Database 10.11.12

Possible Locations of Data Dropout RTDMS Reports (and/or RTDMS ISG) to RTDMS database interface RTDMS Server to RTDMS Database interface ePDC to RTDMS Server interface problems ePDC input and/or output configuration problems Problems on the inbound ePDC stream (e.g. T.O. PDC/PMU problems, PMU installation problems, etc.) 10.11.12

Review Process Dropout Location Identification Severity Classification From end-point back to source Severity Classification Minor – less than 1% loss of data Moderate – 1-5% loss of data Severe – greater than 5% loss of data Issues may be recurring or non-recurring Likely cause determination 10.11.12

Data Sources for Investigation Extracts from the following sources for a 24 hour period will be used to analyze data quality: ERCOT RTDMS Data Base ERCOT Phasor Archiver Data Base (from ePDC) AEP Phasor Archiver Data Base this represents the stream being sent to ERCOT Oncor recorded PDC Output Stream 10.11.12

Likely Causes of Data Loss Application configurations, including ePDC I/O settings RTDMS Server settings Database Database scripting errors Database to server configuration problems Hardware Improper host machine configurations Physical network or firewall problems Source Measurements/Incoming Data Improper or undocumented PMU/PDC configurations Unavailable or dead PMU signals Communication link between TO PMU/PDC to ERCOT ePDC Firewall, Router, IP address issues 10.11.12

Likely Solutions The difficulty of identifying a cause, and the time and resources required to implement a solution may vary considerably for different problems. In general, Configuration issues will be fairly easy to identify and eliminate Database and hardware-level problems may be straightforward to identify at a high level, but difficult to pinpoint if the cause is an individual piece of network hardware or a corrupt database. Incoming data dropouts will be relatively easy to identify after local problems have been eliminated, but solutions will require cooperation with the entities that manage and document the remote PMU or PDC installations. 10.11.12

Study Plan Select date for data base extract AEP-ERCOT data stream intermittency (mid-September) has now been resolved Extract the data and send to EPG EPG will perform analysis, recommend configuration tuning and potential network/server interface adjustments EPG will prepare a summary report and recommendations 10.11.12

Questions 10.11.12