A Python Based EMT Model Quality Testing Tool

The growth of inverter-based resources (IBRs) and less on-line synchronous generators would lead to a decrease in system strength, also called weak grid. Planned or forced outages on the transmission grid could further reduce the system strength. Most the IBRs connected to the transmission grid today require a certain level of system strength for reliable operation. Abnormal responses, such as oscillatory responses or trips could occur under weak grid conditions. To better understand IBR response and assess the system stability under weak grid conditions, electromagnetic transient (EMT) study incorporating high bandwidth EMT models are required because the positive-sequence electromechanical dynamic models and assessments are generally considered inadequate for the weak grid conditions. Therefore, the need of large scale of EMT study is on the horizon and the fidelity of the individual EMT model is imperative for the system wide evaluation and conclusions. A python-based PSCAD model quality check tool, PsCad Auto Run (PCAR), was developed at ERCOT to assess individual IBR's PSCAD model performance under various tests and system conditions to identify any abnormal or suspicious responses that need to be investigated and corrected. The benefit of applying this tool includes the identification and correction of suspect individual model performance prior to utilization in large scale PSCAD studies. The schematic of the PCAR tool is presented in this paper and its application in the ERCOT's large scale PSCAD study in a region with high penetration of IBRs.