What does Dynamic Reserve consist of in terms of generator and system load?

Dynamic Reserve refers to the capacity available from generators that can be brought online or can increase output in response to a sudden change in system load, particularly during frequency events. This capability is critical to maintaining system stability and reliability.

The correct answer encompasses both reserves on generators and system load that utilize under frequency relay protection. This means that as system frequency decreases (typically due to a sudden increase in load), under frequency relays can activate generators to provide additional power, thus stabilizing the grid. This coordination allows the system to respond quickly to changes, making it a vital feature of power system operation.

The other options do not accurately reflect the comprehensive nature of Dynamic Reserve. Simply having manual adjustments doesn’t ensure a fast enough response to sudden events. Reserves exclusively from mechanical sources lack the broader operational context necessary for dynamic response, and static reserves from battery systems do not account for the dynamic nature of the load and frequency adjustments required in real-time situations. Therefore, the integral combination of generator reserves with under frequency relay protection captures the essence of Dynamic Reserve, making it the correct choice.