Real-Time Voltage Security Assessment (RTVSA) Report on Algorithms & Framework

Currently CA ISO's real time operations do not have a real-time dispatcher's Voltage Security Assessment tool and corresponding wide-area visuals to effectively manage the voltage and VAR resources on the transmission system and to identify the following:

• Voltage security margin calculation
• Worst-case contingencies leading to voltage collapse
• Abnormal reductions of nodal voltages
• Contingency ranks according to a severity index for system problems
• System conditions with insufficient stability margin
• Weakest elements within the grid
• Controls to increase the available stability margin and avoid instability

The objectives of this report are to present a comprehensive survey of algorithms available worldwide for the purpose of performing voltage security assessment, make recommendations on the most appropriate techniques, and describe a framework along with the algorithms that have been included in the prototype RTVSA tool.