Overview

Grid Code Load Flow is used to determine a renewable power plant's reactive power capability at the Point of Measurement (POM) under normal operating conditions. In just one Grid Code Load Flow calculation, hundreds of Load Flow scenarios are run at different voltage setpoints by incrementally adjusting the MW and MVAR output from each renewable source (a process also known as 'sweeping'). All results are then compiled to obtain the total output at the POM. Upon completion, Grid Code Load Flow generates a comprehensive report including compliance details, alerts, and all of the power plant assets input data. The report includes a visualization of the power plant P-Q and V-PF capability against grid interconnection requirements including an intuitive representation of any discrepancies and compliance validation.

Key Features

Dedicated Module: Fully integrated with ETAP Digital Twin modeling with unique capabilities for renewable power plant reactive power capability studies. Adaptive Capability Sweeping: Grid Code Load Flow performs hundreds of load flow studies in batches, also known as 'Sweeping'. Based on power plant settings and user defined sweeping data, Grid Code Load Flow runs P-Q sweeping and V-PF sweeping in batches. This adaptive sweeping approach reduces simulation time while maintaining accuracy.

• Assign the assets' power dispatch priority and equipment capability curve either individually or globally through the study case. 
• Define and save voltage setpoints for P-Q sweep, MW setpoints for V-PF sweep, and sweep resolution in study case.
• Choose whether to consider or ignore critical and marginal alerts in the final sweeping result.
• Study case automatically includes non-zero default values that work for a typical P-Q and V-PF study. Comprehensive Reporting: The study result provides a detailed and visual report in excel format using the project data, study settings, and the device and grid capability rules that were used in the Grid Code Load Flow study. 
• Obtain clear visualization of power plant capability results against grid requirements in both tables and charts.
• Examine the charts to easily evaluate compliance and identify discrepancies.
• Tabulated alerts help to determine which asset play a role in limiting the capability curve. Equipment Rulebook:  Choose predefined equipment from the ETAP Capability and Control rulebook , or directly enter assets’ reactive power capability curve.
• P vs. Q or P vs. PF format, at different voltage levels
• Optionally include an extrapolate curve when asset’s operating voltage falls outside the pre-defined range Grid Code Rulebook:  Select a predefined grid code from the ETAP Capability and Control rulebook to validate if the power plant capability meets code requirements for your region. ETAP is continuously adding new rulebook data to cover more regions. Alternatively, custom rulebooks can be added following this format: 
• P-Q requirement: Grid required reactive power capability at different active power values
• Q-V requirement: Grid required power factor capability at different voltage levels

Benefits

• Eliminate manual analysis with an easy-to-use study process
• Save setup time with full integration with the ETAP model
• Obtain comprehensive results from just one study calculation
• Ensure accurate study results by using predefined rulebooks
• Prevent operating constraints by implementing alert settings

Common challenges solved by Grid Code Load Flow

Complex Standards and Codes: Uncertainties that the study will accurately consider all the relevant standards and codes Grid Code Load Flow ensures the consideration for grid interconnection requirements for renewable power plants and systems, including but not limited to these performance requirements: 

• Voltage and frequency ride-through
• Active power control
• Reactive power control
• Dynamic active power support under abnormal frequency conditions
• Dynamic voltage support under abnormal voltage conditions
• Power quality
• Negative sequence current injection
• System protection Time-consuming Manual Processes: Inefficient use of time researching standards running numerous load flow scenarios and compiling the results. Grid Code Load Flow ensures compliance with grid interconnection requirements and saves significant time by addressing various operating limitations and producing multiple studies in just one operation.