There are several ways to keep the output voltage of diesel generators stable:

Using a voltage regulator: This is a device that automatically adjusts the generator output voltage to maintain a consistent level.

Load Balancing Generator: Distributes the load across all available outlets on the generator to ensure no one outlet is overloaded. This will help prevent voltage fluctuations.

Use a voltage regulator: This is a device that helps maintain a steady voltage output by smoothing out any sudden spikes or dips in the generator output.

Perform regular maintenance: Keeping your generator in good working order will help prevent voltage fluctuations. This includes keeping fuel clean, replacing worn parts and regularly checking generator output, among other things.

Using a frequency converter: If the generator produces voltage at the wrong frequency (too high or too low), it can cause voltage fluctuations. The frequency converter can help stabilize the output of the generator by adjusting the frequency to the correct level.

Using a Power Regulator: A power regulator helps stabilize the generator's voltage output by filtering out any spikes or dips in voltage. This helps improve the overall quality of the power output.