Grid reliability, resilience and flexibility system conditions system blackouts

PREVENTION:

• analyses of previous blackouts
• improved system design
• system operation with sufficient margin (lines loading, security, voltage, frequency)

Large blackout in the USA and Canada 2003 (Source: IAEA)
The Energy Community Secretariat IAEA Workshop on Power Systems and Markets, 15-07-2021
GRID PERFORMANCE
Frequency in European grid during the solar eclipse
Source: ENTSO-E
STABLE AND RELIABLE GRID

• FREQUENCY IS CONTROLLED WITHIN +/– 1% OF NOMINAL FREQUENCY FOR THE MAJORITY OF THE TIME
• FREQUENCY MAY GO OUTSIDE +/– 1% FOR SHORT PERIODS ON A FEW OCCASIONS PER YEAR, TO A LIMIT OF AROUND +3% AND –5%
• VOLTAGES ARE WITHIN PERMITED RANGE IN ALL NETWORK NODES
• CURRENTS ARE LOWER THAN ALLOWED
• POWER EXCHANGES ARE WITHIN PLANNED VALUES
• ELECTRICITY PRODUCTION IS NOT RESTRICTED, ALL CONSUMERS ARE SUPPLIED

• SUDDEN LOSS OF ANY FACILITY DO NOT LEAD TO UNACCEPTABLE SYSTEM CONDITION
• NETWORK IS ABLE TO SURVIVE SINGLE FAULT OR MULTIPLE FAULTS
• POWER SYSTEM IS CAPABLE TO REOPERATE QUICKLY AFTER EXCEPTIONAL FAULTS

The Energy Community Secretariat IAEA Workshop on Power Systems and Markets, 15-07-2021
HIGH VOLTAGE POWER LINES CONNECTING TWO OR MORE COUNTRIES

• AC interconnections (equal frequency)
• HVDC interconnections (different frequencies)

ELECTRICITY INTERCONNECTIONS
Interconnectors between Bulgaria, Greece and Turkey
Source:ENTSO-E
ADVANTAGES:

• sharing of generation reserves (lower capital costs for power plants)
• emergency electricity exchanges
• market activities
• more flexible transmission system operation
• increased power system reliability
• higher power system inertia – more stable frequency