Hydro-Québec's challenges and experiences in on-line DSA applications

Hydro-Quebec has a long interest in on-line dynamic security assessment (DSA) necessitated by its challenging power network dynamics (transient, fast and slow voltage collapse). We are presently using off-line calculated security indicators and an on-line monitoring system approach. Every 5 seconds our system provides dynamic security limits, the impact of each out-of-service component, simple guidelines to aid in preventive/corrective control and security-margins which modulate certain special protection systems. These limits are extensively used off-line in the operating and planning environments to ensure security-result coherency for maintenance planning, day-ahead scheduling and ATC calculations. These security indicators are based on topological data and operating conditions. In this context of this high-performance mission-critical system, this paper discusses the practical challenges and experiences of our implemented DSA system as well other specific components including: state estimation, soft knowledge, contingency analysis, performance, equipment limit sensitivity, reliability, responsibility and on-line/off-line coherency.