What is Droop setting in Governor of Generators? How Load of Generators in parallel is controlled?

Summary

In this video, the concept of droop characteristics in generators is explored, highlighting its significance in controlling the load share of parallel generators. The video explains the difference between Isochronous and droop modes, with a focus on speed droop settings in generator governors. By adjusting the reference speed, the load share of multiple generators can be managed. An example demonstrates how generators in droop mode share the load based on droop settings, with the frequency remaining stable at the bus frequency. The video concludes by emphasizing the role of droop in efficient power distribution across generators.

Takeaways

• 😀 Droop characteristics of generators are important for controlling load sharing when multiple generators are running in parallel.
• 😀 Isochronous mode is suitable only for single generator operation as it doesn't allow load share control between generators.
• 😀 Droop setting allows for the control of load sharing in parallel generator operation, ensuring proper distribution of load.
• 😀 Speed droop and voltage droop are the two main types of droop settings used in generator operation.
• 😀 The formula for droop is: (No load speed or frequency - Full load speed) / No load speed.
• 😀 As the load on a generator increases, the frequency (or speed) of the generator decreases due to the droop characteristics.
• 😀 The droop setting is used to control the load share between generators in a parallel operation scenario.
• 😀 In the example provided, two generators (G1 and G2) supply power to a bus with a total load of 1000 MVA.
• 😀 Generator G1 is loaded at 50% with a 2% droop setting and delivers 250 MVA at 50.05 Hz, while G2 delivers 150 MVA at 50.05 Hz.
• 😀 By increasing the reference speed for G2, its load can be increased to 100%, delivering 300 MVA, while maintaining the bus frequency at 50.05 Hz.
• 😀 In dual generator setups, one generator can operate in isochronous mode while the other operates in droop mode to manage load distribution effectively.

Q & A

What is the droop characteristic of generators?

Droop characteristic refers to the decrease in speed (frequency) of a generator as its load increases. This helps in controlling the load share of generators running in parallel.

Why is droop mode used when generators are running in parallel?

Droop mode is used to control the load share of multiple generators. It allows generators to automatically adjust their load based on their individual capacity and the frequency of the bus, ensuring that the load is distributed effectively.

What is the difference between droop mode and isochronous mode?

In droop mode, the load share of generators can be controlled by adjusting the reference speed, whereas in isochronous mode, the generator's speed remains constant regardless of the load. Isochronous mode is typically used for a single generator, while droop mode is used for multiple generators in parallel.

What is the significance of droop setting in generators?

Droop setting helps control the load distribution between multiple generators. By adjusting the droop setting, the load share between generators can be balanced, ensuring that the system operates efficiently.

How is the droop percentage calculated?

The droop percentage is calculated using the formula: (No load speed - Full load speed) / No load speed. This gives the percentage by which the generator's speed decreases as the load increases.

How does load affect the speed of a generator in droop mode?

In droop mode, as the load on the generator increases, its speed (or frequency) decreases. The generator adjusts its output to match the load, maintaining the bus frequency while reducing its speed slightly.

Can the load share of generators running in parallel be controlled in isochronous mode?

No, in isochronous mode, there is no control over the load share. The generator operates at a constant speed, so any changes in load demand are handled entirely by the generator, which can lead to imbalance if multiple generators are involved.

What happens if two generators are running in parallel, one in isochronous mode and the other in droop mode?

In this setup, the generator running in isochronous mode will handle any additional load demand, while the generator running in droop mode will adjust its load share based on its reference speed setting. The droop mode generator adjusts its output according to the frequency of the bus.

How can you change the load share of a generator in droop mode?

The load share of a generator in droop mode can be controlled by adjusting the reference speed or frequency setting. Increasing the reference speed will load the generator more, while decreasing the reference speed will reduce the load on the generator.

What is the impact of a 2% droop setting on a generator’s load?

A 2% droop setting means that for every 2% decrease in speed, the generator will take on more load. For example, with a reference speed set at 50.10 Hz, the generator will decrease its speed to 50.05 Hz as its load increases, thus managing the load share with other generators.