FGMO

How does FGMO impact grid stability?

Free Governor Mode of Operation (FGMO) significantly influences grid stability. Let’s explore how:

Background on FGMO:

• FGMO allows speed governors in power plants to operate freely across the entire frequency range.
• Traditionally, utilities restricted governors within a narrow frequency band, preventing them from responding to frequency changes.

Impact on Grid Stability:

• Enhanced Frequency Control: FGMO enables smooth control of frequency fluctuations. Governors respond promptly to frequency changes, maintaining stability.
• Avoiding Large Frequency Dips: FGMO prevents abrupt frequency drops during unit trippings. For example:With 10,000 MW generation on FGMO and a 5% droop, the system stiffness increases by 2,500 MW per hertz in the Central grid1.
• Reduced Stress on Other Plants: When a plant’s output remains constant despite frequency changes, it forces other plants to work harder to support grid stability.
• Grid Operator Challenges: FGMO can make it more challenging for grid operators (transmission companies) to restore stability promptly,

What is the droop characteristic in FGMO power plants?

The droop characteristic in Free Governor Mode of Operation (FGMO) is a fundamental concept that influences power plant behavior and grid stability. Let’s explore it further

Droop Control Overview

• Droop control is a proportional control mechanism used in power plants, especially those with rotating machines (such as generators).
• It allows the plant’s output to change in response to frequency deviations, maintaining stability within the grid.

Definition of Droop

• In FGMO, the droop characteristic is defined as speed regulation (often referred to as “droop”).
• It expresses the percentage speed rise for which the generated power will change by 100%1.
• Essentially, it ensures that the plant output varies proportionally with frequency changes.

How FGMO Utilizes Droop

• When a power plant operates in FGMO, its governors allow the output to adjust freely across the entire frequency range.
• Unlike traditional modes where governors are restricted to a narrow frequency band, FGMO responds dynamically.
• The droop characteristic ensures that as the grid frequency changes, the plant output follows suit.

Impact on Grid Stability:

• FGMO prevents abrupt frequency drops during unit trippings.
• By allowing the plant output to change with frequency deviations, FGMO contributes to grid stability.
• Other power plants in the system also adjust their outputs based on the same droop characteristic.
• This coordinated response helps maintain overall grid stability and prevents cascading failures.