Load Dispatching 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 Load Dispatching flashcards as text
What is 'inadvertent interchange' and how does it affect a control area?
Answer: Unintended power exchange across tie lines that accumulates over time, requiring payback to affected areas
Inadvertent interchange is the unplanned difference between actual and scheduled tie-line flows that accumulates over time and is tracked for eventual repayment.
How does governor droop affect a generator's response to a system frequency drop?
Answer: The governor automatically increases the generator's MW output as frequency decreases, with the amount proportional to the droop setting
Governor droop is a proportional control where a decrease in system frequency causes the governor to open fuel/steam valves and increase generator MW output automatically.
What is the role of 'supplemental reserve' (also called 'non-spinning reserve') in load dispatching?
Answer: Generation capacity that is off-line but can be synchronized and delivering power within 10 to 30 minutes
Non-spinning (supplemental) reserve is off-line generation that can be started and loaded within a specified time (typically 10–30 minutes) to replace capacity following a contingency.
A dispatcher is coordinating a 'hot start' of a steam unit. Compared to a 'cold start,' what is the key difference?
Answer: A hot start requires less time and fuel because the unit's boiler and turbine are still warm from recent operation
A hot start is faster and cheaper because residual heat in the boiler and turbine reduces the warm-up time and fuel required to bring the unit to synchronization.
Which condition would most likely trigger a dispatcher to implement 'emergency energy' procedures?
Answer: Spinning reserve has been depleted following multiple generator trips and the system cannot meet load from committed resources alone
Emergency energy procedures are invoked when normal reserve resources are exhausted and the system cannot maintain reliability without external emergency assistance.
What is the function of 'load shedding' as a last-resort tool in dispatch operations?
Answer: Deliberately disconnecting blocks of load to prevent total system collapse when generation is critically insufficient
Load shedding involves intentionally de-energizing portions of the system to reduce total demand and prevent a widespread blackout when generation cannot meet load.
In the context of load dispatching, what does 'reactive power management' primarily influence?
Answer: Voltage levels across the transmission system, which affect both system stability and thermal loading of lines
Reactive power (MVAR) management controls voltage profiles across the network; insufficient reactive support leads to voltage collapse, while excess can cause overvoltages.