Any engine is able to cope with a certain sudden jump or drop in load; if this jump or drop exceeds these limits, the engine can stall.

Diesel generators can cope with large amplitudes due to their technical characteristics like max torque and due to the diesel injection system.

Gas generators are more sensible. Normally they can cope with sudden amplitude of at least 10% of their installed capacity which they compensate within about 15 seconds; i.e. if your 2.400 kW engines run with 1.800kW an instant change of 240kW to the upside or to the downside can be compensated from the engine itself. After about 15 seconds the gas generators have adjusted their settings again. If during night a 250kW generator is running with about 140kW, the amplitude is only about 25 kW either side.

To be able to cope with larger amplitudes we recommend installing an additional Central Load Stabilizer (CLS).

The CLS has a defined range within it can stabilize the system versus jumps or drops. The ratios between both directions can be modified according to the client’s demand profile:

• during low demand period normally only the smallest generator is running. During this period the system is more sensible versus sharper demand jumps than drops. During this phase the CLS will build up and keep a lager stabilization range to the upside.
• during high demand periods all available generators are operating. During this phase the risk for strong jumps is very remote but a sharp demand drop can have a strong impact onto the standalone system.

There are some reasons to install a CLS:

1. To cope with short term amplitudes in your daily demand to avoid your gas generators to stall. If amplitude exceeds the generator capacity the CLS capacity supports the system by increasing the possible amplitude. The capacity of the CLS can be adjusted. As it needs some energy (between about 2% to 4%), the idea is that by adjusting your power consumption you try to reduce the additional CLS demand as much as possible.
2. When you start the standalone system you normally add your generator system with larger blocks of loads at once. To avoid stalling your generators with such large amplitude you can “tell” your CLS to build up a load reserve short term. If now you add the load block, the necessary power gets taken from your uploaded CLS.
3. If for any reason you have to take a larger block of loads from your system at once, your CLS takes the additional load before releasing it slowly to the generators.