Practice Test Geeks(SOPD) System Operator/Power Dispatching Practice Test
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Frequency Control Flashcards

7 cards from real SOPD practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Frequency Control flashcards as text

  1. A control area's frequency bias (B) is set at -500 MW/0.1 Hz. If frequency drops by 0.2 Hz, how many MW should the area contribute to frequency response?

    Answer: 1000 MW

    Frequency response = B × Δf in 0.1 Hz units = 500 MW/0.1 Hz × 2 (for 0.2 Hz) = 1000 MW.

  2. Which operating condition is considered a violation of good utility practice regarding frequency response?

    Answer: Blocking or withdrawing governor response during normal operations to preserve unit life

    Blocking governor response removes the unit's contribution to primary frequency response, undermining interconnection reliability and violating NERC BAL-003 obligations.

  3. What is 'tertiary frequency control' or 'economic dispatch' in relation to frequency management?

    Answer: Longer-term redispatch of generation for economic optimization after frequency is restored

    Tertiary control involves economic redispatch over longer timeframes (15 minutes to hours) to optimize generation after frequency and ACE have been restored by primary and secondary controls.

  4. During an over-frequency event caused by sudden large load loss, what is the appropriate operator action?

    Answer: Reduce generation output or trip generation to rebalance load and generation

    Over-frequency from load loss requires reducing generation (or increasing load/exports) to rebalance the system and bring frequency back to 60 Hz.

  5. What is the function of the Time Error Correction (TEC) program coordinated by interconnection operators?

    Answer: To adjust scheduled frequency slightly above or below 60 Hz to compensate for accumulated clock error

    Time Error Correction adjusts target frequency (e.g., 60.02 Hz or 59.98 Hz) to recover accumulated time error in electric clocks synchronized to power system frequency.

  6. A balancing authority loses its AGC system. What is the operator's primary obligation?

    Answer: Manually maintain ACE as close to zero as practical using available resources

    Without AGC, operators must manually monitor and correct ACE to maintain frequency control obligations per NERC BAL-001 and BAL-002 standards.

  7. Which characteristic of a generating unit determines how quickly it can respond to a governor signal during a frequency event?

    Answer: The unit's ramp rate and governor time constant

    A unit's ramp rate (MW/minute capability) and governor time constant determine the speed and magnitude of its primary frequency response.