Final answer:
Buck boost transformers are used for voltage drop correction on small or minimal loads. They adjust the voltage by changing the turn ratios in the windings, stepping up or stepping down as necessary, but are not suitable for large power transfers.
Step-by-step explanation:
Buck boost transformers should only be used for voltage drop correction when the load is small or minimal. In electrical systems, voltage drop in lines is proportional to current, which leads to a decrease in voltage at the application's end, particularly when the line current is high. Buck boost transformers are designed to correct this issue by either stepping up or stepping down the voltage as needed without significantly altering the load power. These transformers work on the principle that the ratio of the secondary to primary voltages in a transformer is equal to the ratio of the number of turns in their windings. For a step-up transformer, this ratio is greater than one, meaning the voltage is increased, and for a step-down transformer, this ratio is less than one, meaning the voltage is decreased.
It's essential when using a buck boost transformer for voltage drop correction to do so only on small loads because these transformers are not designed for large power transfers and can be less efficient or even cause problems in larger systems. Instead, other correction methods should be considered for significant loads.