Definition of brownout:
A brownout is an intentional or unintentional drop in voltage in an electrical power supply system.During a brownout, your lights will usually dim and may flicker on and off. That's how it get the name brownout.
brownout vs. blackout
However blackout is a complete interruption of power supply. During a blackout, your lights will go off.
Top 3 reasons caused a brownout
1.The power system is overloaded during peak demand
When the demand is close to or exceeds the maximum production capacity of the utility, the utility may intentionally restrict the electricity flow in certain areas.
2.Damages to power lines
Bad weather,such as storms can damage certain parts of the distribution network. This will immediately affect the voltage output in the local power grid, resulting in insufficient power.
3.To repair parts
power companies intentionally drop voltage so their engineers can do some vital maintenance on grid equipment .
Problem&Solution
Generally, both brownout&blackout can cause severely damage to electrical equipments;in order to protect precision instruments and critical power equipment, uninterruptible power supply system are used to prevent impact&damage caused by power outages and brownout.