The frequency difference would have to be small in order to match the voltage

The frequency difference would have to be small in

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Island Operation 27 Voltage (V) range (p.u.) Proposed maximum islanding time (s) V < 0.5 0.16 0.5 ≤ V < 0.8 2.00 1.1 ≤ V < 1.2 1.00 V ≥ 1.2 0.16 Frequency (f) range in Hertz (Hz) Proposed maximum islanding time (s) f > 60.5 0.16 f < {59.8-57.0} (adjustable set point) Adjustable 0.16 to 300 f < 57.0 0.16 Microgrid islanding criteria based on voltage ranges Microgrid islanding criteria based on frequency ranges
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Planned Islanding Operation 28 Planned islanding (pre-scheduled) represents a case in which ICM is islanded for maintenance at the substation. Because it is “pre-scheduled”, the assumption is that load and generation is already closely matched (by operator) to have minimum power exchange at the substation. For testing these situations, circuit breakers at either substations will be manually opened, after preparing the initial conditions. For planned islanding, the following test cases and procedures will be applied: Sub 1 Sub 2 Tie-switch Load CHP PV BESSs Diesel Case PI-1 Normal Normal Open Maximum ON ON ON OFF Open CB11 Successful Island 1 formation with minimum transients Case PI-2 Normal Outage Closed Maximum ON ON ON ON Open CB11 Successful Island formation with minimum transients Planned Islanding Initial Condition Test Contingency Expected Immediate Actions
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Accidental Islanding Operation 29 Accidental islanding represents a case of operator mistake which results in circuit breaker opening without any abnormal condition.
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  • Spring '14
  • MohammadShahidehpour
  • Icm, Electric power transmission, Electricity distribution, Distributed generation

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