Products

On-line Study Voltage Stability Analysis and Enhancement (VSA&E)

On-line Study VSA&E is an integrated computer package developed by BSI for voltage security assessment, enhancement and preventive control in real-time mode or on-line study mode. This tool has been successfully implemented on several power systems ranging from 2,000 buses to 15,000 buses.

VSA&E provides analysis, enhancement control, preventive control and load margin and sensitivity calculations with respect to voltage collapse.

The analysis function provides the following:

• Computation of P-V , Q-V, and P-Q-V curves for base-case and selected contingencies with a variety of load and/or generation variations
• Contingency screening and ranking of a large set of credible contingencies in terms of load margins to voltage instability
• Identification of severe contingencies with zero or negative load margins
• Computation of exact voltage security load margin of a specified contingency list
• Computation of the exact load margin to voltage collapse for base case and each top-ranked contingency.

The enhancement control function provides the following: when the load margin to voltage collapse for the base case or selected contingencies is not sufficient, VSA&E determines effective enhancement controls to increase the load margin by exercising all the following level-1 control actions before resort to load shedding. Level-1 Control selects from the following controls: (1) reactive power-compensating devices, (2) ULTC, (3) phase-shifters, (4) real generations and (5) generator terminal voltage. Level-2 Control selections include load-shedding locations and amount of load-shedding to be performed.

The preventive control function provides the following: when the load margin to voltage collapse for the base case is sufficient, yet the system may still suffer voltage collapse should certain critical contingencies occur, VSA&E determines effective preventive controls to increase the load margin for counteracting critical contingencies by exercising all level-1 control actions before resort to load shedding.

Field Proven VSA&E

One of the largest Electric Power Regional Transportation Organizations (RTOs) in the East recently conducted a thorough evaluation of all credible Voltage Security Assessment tools. The evaluation concluded that BSI’s VSA&E consistently surpassed the competition in terms of superior performance and quality results. The evaluation led to a VSA&E implementation contract award for BSI. The VSA&E system is being tightly integrated in the RTO’s real-time EMS environment. The system features two modes of operation. The on-line mode offers periodic voltage security assessment and control and the study mode of the system allows all users to easily execute shared planning activities and cooperative problem study and solving to mitigate potential operating shortfalls in voltage security. It can be also used for operational planning.